D&D 5E Low level healing to stay up in a kids game

[Arvok]

If you're willing to use items from Xanathar's you could give the sorlock a Ruby of the War Mage so she could use her weapon as an arcane focus and still use a shield. It's only an uncommon item that would allow her to use a shield and improve her AC. That's not a complete solution, but if you can decrease the number of players needing healing all the time the bard might be able to keep up better and do more bard stuff.

 

[Domf87]

So, one of the games I run is for my kids and niece and nephew. They have a drow rogue (scout) 4, a red dragonborn barbarian (ancients) 4, a half-elven sorcerer (wild magic) 3 / warlock (hexblade) 1, and a eladrin bard (glamour) 4. The rogue is melee focused and the sorlock often is in melee as well.

Having the character hit zero is a traumatic experience, and they attempt a lot of pre-healing to prevent that. Which, as everyone knows, is not the best in 5e. On top of that, the bard is the only healer (plus some potions) and is doing things like using 2nd level slots with Healing Word and getting roped into being a faux heal-bot. I've even "forgotten" the rules a few times and allowed casting a bard spell the same round as the bonus action healing word just to let them do something bard-like. (And the player wants to be a bard, not a heal-bot.)

I'm looking for ideas I can do to help shift and lighten the healing load. I've pointed out several times the tHP from the bard's Mantle of Inspiration to the player, but it's never seen use. The sorlock doesn't want a shield (hexblade gives proficiency) because she wants a hand free for casting - and aesthetics. She has the Shield spell, but has been using Hellish Rebuke if hit instead. The rogue does their best and has a good AC but has the lowest HP in the party. And does like to take a second d4+0) attack with an offhand dagger rather than disengage and move back. She's rather bloodthirsty. (The barb is just fine, just he's not the only one getting attacked.)

I've floated the idea of having a healing sidekick with them, but the players aren't up for that. I do want this to be a training game to some degree so I'm not going to load them up with lots of defensive magic items or a staff of healing (rare) at this level. Heck, even if I gave a staff of healing, it would still be a single character (and that's the bard again as the only one who can attune) dedicating their actions to using it.

I'm detuning combat encounters to some degree, but remember they are mostly calibrated not to go down which takes a lot mroe resources than popping up after going down.

Assume the players are happy with their characters, so no one is rerolling a new character and the rogue is staying primary-melee and the sorlock as occasionally melee. And that I don't want to flood them with items that change the experience.

So, what are your ideas? Out of the box or in plain sight that I've overlooked.

Let them use potions (on themselves) as a bonus action in combat. Or maybe let them find a healing sprite totem that is 1x day and lasts a minute. Boom, done.