My friend gave me great advice regarding the sippy cup and it worked.
I think you're doing the right thing by putting it on the tray to let her get used to it. Still give her the bottle, but put the cup on the tray. We tried the sippy cup at 10 months and had meltdowns, so we waited til 12 months to give him the formula/milk from it. In the meantime, he got water in the sippy for snacktime.
We did one week with both a bottle and a sippy cup with 2 ounces of milk in it for meal times. The next week, we took away the bottle completely and did all sippy cup. What was key for us was to let him have both the sippy cup and food at the same time.
I was so worried he wouldn't transition, but it was so silky smooth I don't know why I got nervous in the first place!