You need belly support! I also had bad separation and especially when we are talking 3 or more kids it can impact. I would suggest that everyone near you tries their darndest to have you not doing much other than caring for the new squishy. My midwives even got cross if they saw me getting up to answer the door when they arrived! they really expressed the need for rest and recovery. I wouldnt really try to do many pelvic floor exercises in that first week or so. just let your body recover and let those muscles get back into place for a bit on their own. and then start gently with the pelvic floor stuff.