Re: Formula at 9 months
You could try a supplemental feeding system. That way she's getting the formula while nursing. She can have both breastmilk and formula simultaneously, or you can pinch the tube to the feeder to cut off the formula if you want her to have breastmilk only (might be a good idea to wait for your breast to empty before releasing the formula so your supply isn't affected). You can find them online for less than $20.
Wife to my bestie and a SAHM to my sweetie