would it be helpful for the baby to be taken care of away from the mom for a day or two?
depends on if the baby is only breastfed and how old they are...also depends on the babys personality. In my experience there is no black or white answer when it comes to kids!
1. The mom is on board with it. If mom thinks a few days off would help her, then sure, but I never want to see women pressured to leave their babies (unless there's a safety issue).
2. The break enables treatment for ppd, or is otherwise part of a plan for addressing the issues behind it. PPD is generally believed to result from the combination of hormonal changes and the lifestyle changes caused by new parenthood. If the plan is to give Mom a weekend off, and then leave her alone with the baby for the next six months... no, not helpful.
There's possibly more. It's complicated, and it's a very emotional area where you want to tread carefully. Given the username "mother in law", tread extra carefully. Are you giving the impression that you want to help, or the impression that you think she's not good enough for your grandchild?
In most cases, I think PPD is an "everyday" problem - it's a problem every day, so you need a solution that works in the context of your everyday life. You can't fix it by going on vacation. PPD will be waiting when you get home. There are some cases where PPD is major and requires hospitalization, and many cases where it could be productively addressed with therapy and medication, and many many cases where things get better when new moms are able to spend time with friends (with or without babies) and have help with household chores. If you're close enough to take the baby for a few days, are you also close enough to pick up some groceries, bring over a casserole, or offer to do some dishes and fold some laundry?
It's possible an overwhelmed mom of a young breastfeeding infant might find it every more stressful to be torn from her baby. But it's possible to take it on a case-by-case.
You have signed in as "mother in law". Do you have a daughter-in-law who is a new mom? How old is her baby? This depends on so many factors.
It might even be helpful for someone to show up at her house, hold the baby while she naps, cook dinner and clean her bathroom for her. I know that when I was going crazy from the sleep deprivation at 3 weeks postpartum, I just needed my mom to hold the baby for 20 minutes while I showered, then sit and watch movies with me while I nursed, then make me snacks.
But it also depends on her symptoms. Is she exhibiting signs of serious depression or psychosis?
Also there is some early/under-explored evidence that breastfeeding helps improve symptoms of PND. So you (general you, not OP specifically) don't want to be doing anything which may disrupt that, especially in the very early weeks.
If you have any reason to believe that there is a risk of self-harm or harm to the baby then please seek urgent medical advice. You can go to your nearest emergency department if it is after hours or services are limited in your area.
If the situation is not at this level of crisis, a big help maybe to care for the baby while mum attends counselling or group peer support sessions or something like that.
Mother of two spectacular girls, born mid-2010 and late 2012