Firstly, MIL treats me like a daughter. She is generally lovely and tries to help all the time (and would be upset if we didn't want the help).My parents-in-law are from a culture where they are are referred to as mum and dad by the son/daughter in-law. They wouldn't stay away even during lockdown so we had to move in with them so we didn't break the rules
When I had my eldest child, I hardly saw my own mum in the first couple of months as my parents-in-law practically moved in to help out. They were always there. Eventually, I spoke to them (with the support of my husband) and arranged times when we would see them (which was every weekend). At least that meant I had time with my little one during the week and made many new friends during maternity leave. We were grateful that they offered help with childcare when I went back to work. My MIL wanted to do all the childcare but I insisted that my mum could help as well (my mum wanted to). My eldest is now over 3.5 years old and we've managed to set up some healthy boundaries. However, I still drive in to see them every weekend as they cannot 'go for more than one week' without seeing my DS.
I'm expecting my second child and my MIL has already talked about us moving in together so she can help out. I've said that I'd like to split the time equally with my mum. MIL even wants to personally care for me if I need it after the birth. I've been firm and said that she is very welcome to see her grandchild whenever she wants, but I would prefer my personal care to be from my mum. MIL doesn't understand as she's my 'mum too'. DH doesn't have a close relationship with his parents so they speak to me much more. Some of their new friends think I'm their daughter and DH is their son-in-law. DH will support me in whatever I say but they'll just badger me instead. How can I be firm this time round as I really don't want a repeat of last time, when I just felt I'd been imprisoned with them? They aren't horrible people at all but this is their culture so my MIL lived with her MIL for most of her life.