I didn't say the question was unnecessary, I said it wasn't as confusing as you're making it by trying to parse out very line of text. It says what it says, there's no hidden meaning. I'm also not sure how that would increase the Rail Golem's Burning? Rail Golem wouldn't even trigger it for a Heal of 0.
As an aside, the Rail Golem and Fire Gamin are the only things she would take that wouldn't benefit from that upgrade (she still has her henchman, totem and minions), and both of those would be crazy overpowered if they did, the RG in particular.
Edit: Actually, since 0 damage is considered no damage, the Fire Gamin wouldn't "heal for 0" either.