I was told by our pediatrician to begin supplementing with formula. She's been exclusively breastfed (and solids/people food) until this point. I was sad to have to supplement, I'd envisioned only nursing or at least pumping until she was one and could begin cow's milk. But she's on the lower percentile for her weight so I decided to try it. I started by making a bottle equal parts breastmilk and formula. LO will not drink it. She just won't. She spits it out.

Is there a right way to transition?