Most formula fed babies drop to 3 bottles around 10 months, some a little earlier. It's not really swapping a bottle for a snack because you change the timing of bottles to do one on wake up, after lunch pre-pm nap and then bedtime.
If she is looking for more then let her have some just make sure it doesn't make her milk intake drop, if it does reduce the solids a bit. If you aren't giving finger foods yet I would start giving her things she can eat herself. Have a look at the baby led weaning posts for help, we gave things like toast fingers and steamed or roasted vegetable strips.
Laura