Frozen Milk advice

Hello!! So I’ve been breastfeeding my 11month old the first month I nearly exclusively pumped while we worked out some latch issues. After that I almost exclusively nurse. But I had an over supply for the first 7 months so I’ve got a pretty good stash of frozen milk that she barely uses. She has bottles when I’m at work but I’m a college professor and only go in to teach classes 3 days a week for a few hours. So some days she will deny the bottle or only drink 2 oz while I’m out. She just waits on me to return home. She’s taken to table food beautifully. She also drinks water through a straw and fresh pressed juice. I’m planning to begin weaning soon. And I want her to use the milk I’ve pumped over the past year even after I wean but she doesn’t seem fond of it. Especially the older milk. She is far more likely to actually drink a bottle if it’s fresh (never frozen) or just recently frozen. So I was wondering if I slightly thawed some older milk not completely but get it slushy and mix it with slushy recently frozen milk and re distribute into new bags. Is there any wisdom against this idea. Or should I just save my older milk for baths and body butters and pump between my classes for the next month let her use the newer stuff til it’s out.