Been away for a couple of days and only just read this thread.
Kittenbaby
Your HV wants lynching, she really does.
Nothing wrong with a 3.5oz weight gain in a week at all. She'd soon be a Michelin baby if she averaged a 7-8oz weekly gain. I know 'cos that is exactly what happened to my DD1 and by six months she was too fat to roll over and actually wheezed whenever she exerted herself! Stupid, stupid HV thought she and I were wonderful .
My DS, in contrast, only ever avaraged a 3-4 oz weight gain and soon dropped from the 95th percentile to the 9th and stuck there. HV tried to make me give up bf and ff instead but DS proved to have cows' milk intolerance and wouldn't countenance soya milk so went back to breast within 3 days (fortunately not off long enough to affect supply particularly).
It sounds to me like your DD is thriving fine and you and your DH are doing a grand job between you. Continue to concentrate on you and DD and don't start helping with chores until you feel able.
My kids are now teenagers and bright, healthy and normal. Neither is very tall for their age but then my DH and I are only 5'7" so they were never going to be giants! However they are not particularly small either so don't worry. All kids are individuals and find their own level. Weight gain will vary from week to week anyway. Even DD1 had the occasional week when she only put on an ounce or two (but then she'd make up for it with a 10/11oz gain the next week!)
Keep your chin up love. You're doing fine!