MIL comment to her son

I would take offense to it if she said it with me there. The implication is you are not there for your husband.

Reading your post, it looks like you feel the same way as me. I would suggest if something makes you uncomfortable. You can say “please stop, this makes me uncomfortable.” If they challenge you or ask you why “please stop because this makes me uncomfortable.”

You don’t owe anyone a reason for why something makes you uncomfortable, or look for justifications to how you feel. Another thing “is it just figure of speech?” You also don’t need someone else’s intentions to acknowledge the impact it had on you.

I think that depends on how much weight your partner is actually pulling. If he's one of those men that leaves a lot to the women, then I'd definitely have something to say.

I’d say me and my partner are equal in terms of responsibility. I carry all the mental load though. He’s good at dropping and collecting the kids. However I’ve had 3 kids in the last 3 years and exclusively breastfed each of them plus still breastfeeding my 8 month old so it’s not like I’m doing nothing

So I don't know your mil. But I know i get told a million times to take it easy. But if I heard my mil tell my husband that. Idk how I'd take it i guess depends on her tone. I know once she made a comment something like this when she cane to visit us right after I just got home from a visit with all 5 kids & my disabled mother. My husband stood home alone chilling. And she pissed me off.

I don't take it like that at all. He is just one person, just like you're one person. The meaning of that phrase is typically like, don't overexert yourself trying to take on the workload of multiple people, etc. I would certainly take offense if she said something like "you're doing so much by yourself."

That being said, I don't know your relationship with your MIL so maybe there's some animosity or contention there. But just based off this post alone I don't think her comment is meant to offend you.