No worries, I was in a simular situation to you 7 weeks ago when my cat had an unplanned litter of kittens and everything she did worried me.

One thing I would suggest is that you weigh them (just in some little kitchen scales) they should be putting on a noticable amount of weight each day (about 10grams I think). If you weigh them daily, then you will be able to see that they are all feeding ok.

GoodLuck! You and Mum are going to do just fine!