MIL telling me no co sleep

So my MIL is constantly harassing me on how I shouldn't co-sleep. We have a routine my baby has a bath, boob, and falls asleep in her crib at 7:30. She wakes up around 3 and goes in our bed with us till the am. My MIL is always saying my boys were in their own room by 4 weeks and your going to spoil her. SHE IS 6 MONTHS OLD. I work during the day from home so I need my sleep too. She even complains that we have a mini crib in our room instead of her sleeping in her crib across the house in the nursey. I feel like I can never win😥 I normally wouldn't care but it bothers me cuz she is my MIL and I feel like she's never gonna act like I am as good of a mother as she is.