As usual when dealing with contingency, ambiguities abound.
The one thing that is pretty certain is, yes, you can share contingency with a familiar. Nothing in contingency bars you from doing so, and it otherwise meets the criteria described by share spells. Since it’s a single casting, that just “affects” two targets, you only need—and, importantly, only can use—a single focus statuette.
That brings us to the first problem: the statuette has to be “of you.” Is that “you” the caster, or “you” the subject? Or does it have to be both simultaneously?
If “you” is just supposed to be the caster, then there’s no problem: you and the familiar can both benefit from the same statuette that depicts you.
If “you” is required to be the subject, then it’s unclear if a statuette depicting both yourself and your familiar would count as a statuette “of you” and “of your familiar” simultaneously, and so be valid for both of you, or if it would count as a statuette “of you and your familiar” and therefore not work for either of you. I would guess that most would accept this, but since we are concerned with strict RAW, we have to note this ambiguity—RAW gives no way to determine the “correct” interpretation, since the English language used is ambiguous and none of these are given stricter definitions in the game rules.
If “you” is required to be both the caster and the subject of the spell—plausible, considering the usual function of the spell—then we have the same question as above, but if the answer is “no” then the familiar cannot get a contingency at all, even if you were willing to forgo your own.
After that, we get to the far more important problem—you have to carry the statuette with you in order for the contingency to function. We have another ambiguity here: is it possible for both you and your familiar to do that at the same time? For example, if your familiar carries the statuette, and you carry your familiar, do you also count as carrying the statuette for this purpose? No one knows! But there is definitely only one statuette, so an answer is needed.
Another ambiguity—if you are separated from the statuette, and then recover it, does the contingency resume? This one is less ambiguous—the phrasing “must carry the focus for the contingency to work” strongly suggests that not carrying the focus doesn’t dispel the contingency, it just makes it inactive. Still, we can’t be certain about that. Anyway, this means that, even if carrying your familiar who is carrying the focus doesn’t work, the two of you can trade the statuette back and forth to control which one of you is the subject of the contingency at the time.
So basically, this comes down to four questions with no unambiguous RAW answer:
- Does a statuette “of you” who is, in the original context of the spell, have to depict the spell’s caster, the spell’s subject, or an individual who is both, simultaneously?
If “caster,” then there are fewer problems, and we can skip question 2.
If “subject,” then we have to worry about question 2.
If both “caster” and “subject,” then we have to worry about question 2., and if the answer is “no” then your familiar can never benefit at all, even if you forgo your own contingency.
- (Moot if 1. is “caster”) Does a statuette of both you and your familiar count as both a “statuette of you” and a “statuette of your familiar” for the sake of contingency?
If “no,” then you will only ever be able to have a contingency on one of you, and which one is fixed at the time of casting. If the answer to 1. was “caster and subject,” then only you will ever benefit.
If “yes,” then it will depend on the answers to 3. and 4.
- (Moot if 1. is “caster,” or if 1. is not “caster” and 2. is “no”) Does carrying your familiar while your familiar is carrying the statuette count as carrying the statuette yourself for the sake of contingency?
If “no,” then you will only ever be able to have a contingency on one of you, but if 4. is “yes” then you could swap which one of you that is back and forth.
If “yes” then you both can benefit simultaneously.
- (Moot if 1. is “subject” or “caster and subject” and 2. is “no,” or if 1. is “caster” 3. is “yes,” or if 1. is “subject” or “caster and subject” and 2. and 3. are both “yes”) If you are separated from the statuette, and then recover it, does the contingency resume its effect?
If “no,” then you will only ever be able to have a contingency on one of you, and which one is fixed at the time of casting.
If “yes,” then you can swap which of you benefits from the contingency at any given time by trading the statuette to one another.
Questions 2. and 4. are “probably” (which I am not going to attempt to assign a weight to beyond “>50% but <100%”) “yes,” but 1. and 3. are really just toss-ups; they could go either way. 3. in particular gets into semantic arguments about “carrying” and philosophical arguments about what it means to possess an object and so on.
A table to make the different possibilities clearer:
| 1. |
2. |
3. |
4. |
Affects... |
| C |
– |
Y |
– |
both simultaneously |
| C |
– |
N |
Y |
whoever holds the focus, can swap |
| C |
– |
N |
N |
whoever held the focus at time of casting |
| S |
Y |
Y |
– |
both simultaneously |
| S |
Y |
N |
Y |
whoever holds the focus, can swap |
| S |
Y |
N |
N |
whoever held the focus at time of casting |
| S |
N |
– |
– |
whoever held the focus at time of casting |
| C+S |
Y |
Y |
– |
both simultaneously |
| C+S |
Y |
N |
Y |
whoever holds the focus, can swap |
| C+S |
Y |
N |
N |
whoever held the focus at time of casting |
| C+S |
N |
– |
– |
only the caster |
If we treat all questions as evenly distributed—which I consider reasonably valid for 1. and 3. but 2. and 4. probably lean more towards “yes”—then there is a one-third chance that contingency will affect both wizard and familiar simultaneously. Affecting whoever held the statuette at the time of casting has the same one-third chance, allowing swaps after casting is a one-sixth chance, and affecting only the caster is also a one-sixth chance.
Note that I did consider one alternative approach, wherein you use two separate castings in order to use two separate statuettes. However, contingency says “You can use only one contingency spell at a time,” not that you can only have one contingency at a time. So the second casting will dispel the first, even if the first was shared with another target and isn’t active on you. This much, at least, is mostly unambiguous. You could argue about the definition of “use” but in context it definitely seems to refer to casting and not merely having.
It probably goes without saying, but for the record, no, of course you shouldn’t allow contingency to be duplicated in this fashion—or any other. Allowing contingency at all can be daunting, but you definitely don’t want to allow any method of overcoming its one significant limitation.
