Aloha from Kauai
@EmmaTheCabbage . Your doing great. For heat source you can warm op a washcloth or just any added warmth for an option. Not sure what island you are on but we are reading high 80's on most so just a little warmth. She needs to be in the 90's during the day being we are humid that should be ok.
You have gotten some great advice. The only thing I would add is that I notice when my chicks are that small they need someone to show then how to eat. I tap with my finger on or near the food like a mamma would. Break it down smaller, soften it, what ever it takes. Once she gets it she will be fine from there.
She does look down, do warm her up ♡, keep her out of any drafts.
She has very unusual colorings for our feral. What island you stay?