BBH night nappy - red marks on thigh

We used a BBh night nappy last night with a wool cover, this morning DD has 2 red marks/welts from the frill/ruffly bit of the leg on the front of her thigh.

We've had this occassionally before but they go in an hour or so, but these are worse and still there almost 12 hrs later!!! I hope they go soon....

Not even sure why it has happened although she now sleeps on her tummy, must have been pressing in there all night :-(

I can't work out if the wool cover would have been covering this area or not, not sure whats gone on. I guess the wee has leaked out the side of the nappy onto the outer bit and the wool hasn't absorbed it.

Anyone had this? Bit nervous about her wearing a nappy again tonight, I dont' wnt ot make them worse, might have to lather with sudocream, its like they are pressure sores, poor DD :-(

I might need to go up a size in nappy???