Need advise

Unsure where even to begin.  For those who have read my messages you know a liltle bit, so will try and make a long story short.  Last winter we woke up to find a stray cat snuggled in one of our chars on our porch.  She stayed there and had somewhere to sleep. She was skinny and we fed her.  She was very very timid but after a few months became trusting of me and now when I feed her she loves her head rubbed.  Just the sweetest thing and I've grown very fond of her.  Our inside cat not so much.  Absolute hates her and would never warm up to her.  Fast forward...she had kittens.  Not here, somewhere else.  But she continues to come to eat.  Is thin and sits on my doorstep and waits for me in the mornings (not every morning, but sometimes (and I don't want to read into this as though she would be sitting here wating for me), however, she comes over to eat and drink out our of bird feeder about 3 times a day).  Here's my dilemma.  We are going to have to move.  I know I can't not move just because of her, but when I think about leaving and they wouldn't have the food I provide I can't tell you how my heart breaks not knowing if she will starve.  I was thinking about going around house to house to find the owners/care takers and talk to them and tell them that she's always hungry, eats here, give them the bird bath she loves to drink from and also a catnip plant that she loves rubbing her head around, but I just don't know what I'd say or how to go about something like that.  My heart is aching so bad I feel like I'm going to be depressed over this situation.  DH says I cannot let that be the factor that keeps us here because we have to move.  Just no question about that one and all the reasons would be too many to list here (and not the subject of what I'm talking about - the cat).   What would you do if you were in my shoes.  If you were to talk to people that owned the cat what would you said (besides your not taking care of your freekin cat you freekin jerks and she's starved and I can see her bones and in the winter she freezes during the winter when you leave it outside at night - cant say that cos it just wouldn't come out right).  I was thinking of calling an animal place in case there are no owners and for some reason no kittens anywhere, but she's been in the neighborhood long before we got here (about 5 years now).  Just don't know what to do and would like to know what you would do.