Sounds like you're just getting problem after problem
We use large sandies or toddle ease with wool and at least one hemp and one cotton booster! And my Charlotte is about the same age as yours
- and a heavy wetter - must be the name
I usually change her every couple of hours - then if I know I want to leave her longer eg. if we're going out, stick an extra hemp booster in. I found I could get plenty of boost in one of these without any leg gape. I'm definately prefering hemp and MF - because we always have to have our massive fleece liner, the MF is never next to her skin so seems to be fine for us. Over night I use two hemp boosters - we've only got stuffins atm and they seem to work well then MF and a cotton mother ease one. And sometimes atm - because she's teething and drinking more, I do change her during one of her night feeds, if I think she's too wet.
I'm going to try interlock with tights - I've had dungies and trousers over wool soakers and not had any problems. She's my only girl too - but I've been putting her dresses over longies. I do like the big bum look tho - she was in a sposie the other day and it just looked odd.....she looked half dressed!
LLS have got 10% off their interlock soakers tomorrow! I've stuck an alarm in my phone so I don't forget
But as others have said - they're only nappies - use sposies if it's not working - I have a pack in the cupboard, cos we go thro so many nappies and inserts and fleeces (especially this week as I'm having to use them double since the teething wee is back), sometimes I run out of one or the other bit and sposies are there as the fall back. It's not worth stressing yourself out over