I don't think you're being too rigid at all. From my experience one of the few things that's worse than feeling overwhelmed and exhausted is feeling like you've compromised your parenting standards. If people don't want to help you on your own terms, then they don't want to help: they want to control. But you already know that 
If you can get people to help with meals and laundry and some cleaning/tidying then you're okay. If you can get a 13 year old in to play with your older kids for an hour a few times a week then you're GOLDEN. This probably sounds ridiculously sunny but one thing that's really impressed me since my twins were born is how much random acquaintances really want to help: neighbors, husband's coworkers, people from church/school etc. If when people offer help you give them something specific to do, it will get done, and you'll have given somebody a chance to do their good deed for the day And you won't need to rely on your mother or MIL, so hooray for that.
If you can get people to help with meals and laundry and some cleaning/tidying then you're okay. If you can get a 13 year old in to play with your older kids for an hour a few times a week then you're GOLDEN. This probably sounds ridiculously sunny but one thing that's really impressed me since my twins were born is how much random acquaintances really want to help: neighbors, husband's coworkers, people from church/school etc. If when people offer help you give them something specific to do, it will get done, and you'll have given somebody a chance to do their good deed for the day And you won't need to rely on your mother or MIL, so hooray for that.
