If my Arcane Trickster's owl familiar is within 5 ft of the enemy, can it both give advantage to the next attacker and trigger Sneak Attack?

Question

My character is an Arcane Trickster and I'm trying to figure out what his owl familiar can and can't do.

I know that if the owl is within 5 feet of the target, it can use the Help action on its turn to aid the target's next attacker:

You [the owl] can aid a friendly creature in attacking a creature within 5 feet of you. You feint, distract the target, or in some other way team up to make your ally’s Attack more effective. If your ally attacks the target before your next turn, the first Attack roll is made with advantage.

I also know that when it's my turn, if the owl is within 5 feet of the target, I can use Sneak Attack:

You [a Rogue] don't need advantage on the Attack roll if another enemy of the target is within 5 feet of it, that enemy isn't Incapacitated, and you don't have disadvantage on the Attack roll.

So let's say I'm adventuring with a character named Bob, and we're in combat, and the order is owl > Bob > me.

Can the owl, since it is within 5 feet of the target,

1. use the Help action to give Bob advantage on his attack AND
2. allow me to use Sneak Attack?

If so, can the owl still use its flyby ability to avoid opportunity attacks?

Answer 1

Nothing prevents this from working, but there is some nuance

The Help action means an ally gains advantage, though the specifics of this are a bit complicated (Do you choose which ally gets advantage? Is it just the very next ally to attack?) But in the scenario described this works either way, with Bob getting advantage on his attack against the target.

Then, once the Rogue's turn comes around, if the Owl is still adjacent to the target, the Rogue can use Sneak Attack. This is because Sneak Attack only works if an enemy of your target is within 5 feet of it, right now.

Note that the Rogue cannot use Sneak Attack if the Owl merely flew up to the enemy and then flew away using Flyby. The Owl must be adjacent to the enemy when the Rogue makes their attack.

Kirt brings up an excellent point and summary:

The owl could also give you sneak attack and still move away safely by readying an action to move after your attack. But then it would not be able to Help Bob. Basically among Help, Sneak Attack, and Safety, you can choose any two.

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Technically, the Owl could fly past, taking the Help action, and, when it is next to the target, the Rogue could use a Readied action to attack while gaining Sneak Attack. This would use their reaction and action from the previous turn, preventing them from potentially using Sneak Attack on an attack of opportunity and preventing them from using a reaction spell, but it is an available option. In this case, the Owl is safe, the Rogue gets Sneak Attack, and Bob benefits from the Help action (assuming the Help action either selects Bob or ignores the Rogue or that Bob also Readied an attack and uses it before the Rogue).