Taking Advantage of That Autism Stubborn Streak

Kalisha has been struggling with her weight for several years. She has tried various things, but her penchant for sweet things has always thrown her off track and any real weight loss has eluded her.  She has never wanted it badly enough and I can't want it for her more than she wants it for herself. She also gets a 'depo' shot every 3 months. It increases her hunger.
She is not only a huge Indianapolis Colts fan, she also likes the Tincaps, a minor league baseball team that plays in our town. She attends many of their games and has purchased several t-shirts with the team logo. However.....she wanted a real team jersey. The cost of $70 was prohibitive, but she saved. She wanted a 3X (they do run a bit small) but all that was available was a 2X. It fits her across the shoulders and bust but is not comfortable around her waist and butt area.
Kalisha joined Weight Watchers. She is thrilled with the app for her phone that she can use on bar codes to check the 'points.'
Here's where the stubbornness or tenacity or perseverance  of her autism diagnosis is a good thing. She wants to fit into that jersey and will do anything to accomplish that goal. It has been almost a month: longer than she has ever stuck with a weight plan before.
She only weighs on Tuesday and Friday mornings. She will not get on the scale any other day. She gets up in the morning, showers, get dressed, and walks the dog. She does her exercises and writes down her points, faithfully, EVERY DAY. She has convinced her cooking class companions to count points and only prepare healthy meals, every Friday.

She has absolutely refused any tidbit of something sweet, no matter what. She has not had a Big Mac (one of her favorites) after she saw how many points were in one.
We have talked a lot about the psychological aspects of this, also. I (and Kalisha) realize you can't be successful at anything without a struggle and she does have to have a little leeway sometimes. I am preparing meals so she and I eat the same things. So far she has lost 5.5 pounds.
I am not naïve enough to believe this is the end of the weight struggle. BUT perhaps, by the time she can fit into that 2X jersey, she will have become so accustomed to healthy eating, it won't be such a difficult lifestyle.
For right now, I am thanking God every day for her single-mindedness.