Baby nappy sizes

Charlie

So my LO is 7 and a half months. She’s over 28lbs(2stone), and is currently in size 7 pampers, and they only go up to size 8. She seems to be going up a size every month. I’ve considered putting her in potty training nappies because they come in yearly sizes but I’ve been told theyre a bad choice because they don’t hold as much wee in them. Does anyone know what I can do when she gets too big for size 8?