New here and concerned about feeding/growth

[OtterGoRun]

Hello all,

I just signed up for this site but probably should have done do awhile ago. I have two ball pythons, one is a little over 2 years old, and the other will be turning 2 next month. I have a question regarding the feeding patterns/growth of them.

The older ball is a PIGGY. He is constantly hungry. We feed him 1X per week, giving him 3 appropriately sized mice (I swear he would eat more if we offered them). He is now 36" long and a few inches in diameter. He sheds and poops on a regular basis, and behavior seems normal. My concern with this guy is that I am overfeeding. Should I not feed him until he is full? Or go ahead and give him what he wants? (Don't really know it's a "he", we just call it that)

The younger ball is the exact opposite. We'll call it a "she" for now. She will only eat 1-2 times per month, one mouse at a time, (we offer weekly). The first winter we had her, she refused all food for months, regardless of appropriate temp and humidity (we did see her drinking water though). The second winter, she ate a little better, but still MUCH less than in the summer months. Her growth is really stunted as a result of this and I am worried about her. She is around 24" but really skinny. (picture below) We have tried all the feeding tricks to get her to eat more often, but she just doesn't want it. She also poops and sheds less often than our other ball, I assume as a result of less food. I am worried about UNDERfeeding this one.

Conditions in both tanks are the same. Same temps, humidity, hides, etc. Is this just a behavioral difference between the two or have I waited WAY too long to take the smaller one to the vet? Thanks!

ETA: I know she had a rough shed this last time (you can see it on the tail). This is the first time she has had a bad shed and we are going to give her the warm bath and towel to get it off.