Breastmilk for toddler?

Would you give breast milk to your toddler? I have a 22 month old and almost 32 weeks pregnant with her baby sister. My 22 month old never got to breastfeed because she was premature and had severe GERD and was put on formula to gain weight. I always have an oversupply of milk, enough for like 3 babies. I was thinking of putting some in her bottle after her sister is born for its nutritional value. Is that a crazy idea or? She would have just turned two and she wouldn’t be breastfeeding but getting it mixed with her milk.