Is it normal for a 5 year old to still drink milk from baby bottle?

My aunt is still feeding my nephew milk on a baby bottle even though he is 5 and she was doing laundry and kid is asking me to feed him. We just had our lunch and he's asking me to prepare him a milk like he's a baby, and if you didn't do it he will throw tamtrums. Of course I didn't do it cuz I thought he's too old for that and my aunt called me selfish. Like he drinks milk 3x a day from baby bottle everyday.
Is it normal for a 5 year old to still drink milk from baby bottle?
Post Opinion