@sara-lou, I'm too soft! I'm 21 and my husbands eldest sister is older than my mum! Honestly I know what you're saying is totally true and tbh I need to do that or at the very least explain to my husband and have him help me do that in the nicest way. Sigh. Gotta grow some balls.

Don't let her cuddle him to sleep then. It's perfectly acceptable to say how he goes to bed & why. I'm sure she'd understand and if not well sod it take him off her & just put him to bed how you usually do. When we visited my husbands family when Morgan was a baby. I'd say at his bedtime 'oh have more cuddles in the morning it's time to go to bed' and I know they were raising their eyebrows at me like ooh so strict. But I thought hey my baby sleeps through the night & non of yours do. What I'm doing is working & I'm not messing with it lol

I know the feeling. The entire weekend my OH invited his eldest sister round every day 3 days straight, she sat with baby in her arms for his full nap. Come Monday he refused to sleep in his crib. I spent 5 hours going up and down the stairs as every time I'd put him down he'd wake again in 10 mins. OH saw all the hard work yet continues to invite his sister round daily to spend time cuddling with my baby :S I can't afford to have you enjoy all the fun of a newborn and me reap the consequences!!