This is your life. MIL or even our own mothers should draw boundaries and learn to respect our privacy. If you can't soften her, get your husband to deal with it and take this matter seriously. Use the covid19 situation to your advantage. Limit to 10 visitors per day, make sure they wash their hands and stand 1m away from you and baby. If you want to add drama, cough in front of your visitor's drink. They will get the message and leave instantly.
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