Combat Medic / Shield Maiden build
Here are some options your fighter has to make it more of a supporting healer.
3 Feats to choose from:
If your fighter is a level 4 variant human, she'll have access to 2 feats. One at level 1 and another at level 4.
If she is a variant human that multiclassed before reaching level 4 or a level 4 fighter of another race, you'll have 1 feat. This assumes you did not pick ASI at level 4. Any other combination leaves you without access to feats.
Choose up to as many as you have access to:
Inspiring Leader
Prerequisite: Charisma 13 or higher
You can spend 10 minutes inspiring your companions, shoring up their
resolve to fight. When you do so, choose up to six friendly creatures
(which can include yourself) within 30 feet of you who can see or hear
you and who can understand you.
Each creature can gain temporary hit points equal to your level + your
Charisma modifier. A creature can't gain temporary hit points from
this feat again until it has finished a short or long rest.
Inspiring leader allows you to buff your team with temporary hit points once per short rest. Having temporary hit points before the start of an encounter is always nice to have.
Healer
You are an able physician, allowing you to mend wounds quickly and get your allies back in the fight.
You gain the following benefits:
When you use a healer’s kit to stabilize a dying creature, that
creature also regains 1 hit point.
As an action, you can spend one use of a healer’s kit to tend to a creature and restore 1d6 + 4 hit points
to it, plus additional hit points equal to the creature’s maximum
number of Hit Dice. The creature can’t regain hit points from this
feat again until it finishes a short or long rest.
The healer feat with the healer's kit allows you to restore a creature's hit points once until the next short or long rest. This is a cheap way to heal without magic but is very limited in application.
Magic Initiate (Cleric)
Choose a class: bard, cleric, druid, sorcerer, warlock, or wizard.
You learn two cantrips of your choice from that class’s spell list.
In addition, choose one 1st-level spell from that same list. You learn
that spell and can cast it at its lowest level. Once you cast it, you
must finish a long rest before you can cast it again.
Your spellcasting ability for these spells depends on the class you
chose: Charisma for bard, sorcerer, or warlock; Wisdom for cleric or
druid; or Intelligence for wizard.
Choosing Magic Initiate will open up spells without the need to dip into a class. A Cleric spell initiate may choose Spare the Dying and Guidance as cantrips and Cure Wounds or Healing Word as a 1st Level Spell.
Spare the dying will allow your fighter to stabilise creatures
without a medicine check nor healer's kit.
Guidance is a support spell that boosts an allies ability check by
1d4.
Healing word is a ranged heal spell that uses up a bonus action and
spell slot.
Cure Wounds is a stronger heal spell but requires an action and has a
range of touch.
Fighter Class Options
"Purple Dragon Knight/Banneret" from SCAG pg 128.
This archetype available to knights at level 3 has the following feature that provides an AOE heal for your party:
Rallying Cry
When you choose this archetype at 3rd level, you learn how to inspire
your allies to fight on past their injuries. When you use your Second
Wind feature, you can choose up to three creatures within 60 feet of
you that are allied with you. Each one regains hit points equal to
your fighter level, provided that the creature can see or hear you.
A "protection" fighting style PHB pg 72 chosen at level 2 keeps with the theme of a shieldbearer/combat-medic type of fighter. She can protect her friends as she runs up to aid them.
Protection
When a creature you can see attacks a target other than you that is
within 5 feet of you, you can use your reaction to impose disadvantage
on the attack roll. You must be wielding a shield.
Multiclass Options
Should you wish to multiclass your fighter either before or after level 4, these are some options available for a supporting healer depending on her stats. Keep in mind that multiclassing before level 4 restricts your access to feats. Note that multiclassing to/from/with fighter requires a minimum strength of 13.
- Paladin (Requires 13 STR and 13 CHA): Immediate access to Lay on Hands
- Druid (Requires 13 WIS): Access to healing word and cure wounds. Wild Shape / Summoning utility at later levels
- Bard (Requires 13 CHA): Access to healing word and cure wounds. Ability to buff allies and debuff enemies
- Life Cleric (Requires 13 WIS): Additional healing ability
- Grave Cleric (Requires 13 WIS): Ranged spare the dying. Maximised heal on creatures with 0 hit points.
Consider these options if your fighter doesn't have enough Charisma and Wisdom to multiclass into the above mentioned classes.
Zealot Barbarian (Requires 13 STR): Requires 3 levels of barbarian but resurrection type spells can be cast on her for free if you ever need to revive her.
Rogue Mastermind (Requires 13 DEX): Requires 3 levels of Rogue. Has ability to "help" when attacking at a range of 30 ft.
Rogue Thief (Requires 13 DEX): Requires 3 levels of Rogue. Has Fast Hands which allows her to use items as a Cunning Action. This means you can feed potions up to twice per round and with action surge you may feed potions up to 3 times per round.
Don't forget that you can always load up on healing potions and use an action to feed them to your ally. I've been in a game where a familiar doing just that prevented a TPK. A fighter, aside from having better stats and standard actions than a familiar, also has action surge to feed potions twice if needed.
With all that said, I recommend you pick:
- Variant human with 4 levels in fighter.
- Pick the Purple Dragon Knight/Banneret archetype
- Protection fighting style.
- Inspiring Leader and Cleric Magic Initiate Feats
After level 4, you may multiclass into one of these:
- Bard if she has high charisma
- Life Cleric if she has high wisdom
- Rogue Thief if she has high dex but low charisma and wisdom
- Zealot Barbarian if she has high strength but low charisma and wisdom
Good luck with your new Shield Maiden!