it's totally normal for a 9month old to still need milk at night. You can try cutting down on night feeds but it's a bit young to totally night wean. To cut down you'd need to make sure they where getting plenty milkand some solids during the day, I'd expect 2 meals a day at this age.
The problem is they can be very distracted and easily only take enough milk to satisfy initial hunger and then wake lots at night for more milk. it's call reverse cycling.
You try offering a dream feed at around 10pm, then sending in someone else to settle at next waking. if they go back to sleep then you know they aren't really that hungry. if not then you'll know they really need feeding.
Even when they stop waking for food many young children still need resettling in the middle of the night. Something like 60% of toddlers don't sleep through every night.