Help- standard minky gave my LO nasty marks on thighs

So last night we officially tested our new rainbow standard minky. I stuffed it with a prefold, a triple LL bamboo insert and a LL bamboo booster, and put a LL fleece liner on top (which was probably redundant). Anyhow, no leaks whatsoever in 12 hours, but this morning we found bright red marks on each of her chubby little thighs (she is about to reach 9kilos and this was a size 2 minky, so is just below the lowest reference for this size, and even though she's a quite tall baby the elastic is still low on her thighs) that up to this time (it's almost 5pm here) have not really faded.

So my question really is, what do I do? Do I sell my two minkies and invest on something else? Do I wash them on 60 degrees with the hope that the elastic will loosen up a bit? Or do I keep them and wait until LO grows a bit more so that the elastic reaches her waist- in which case though, it'd still leave marks, just on a difference place on her body, right?

I've already invested on those (got a couple, one new one preloved, and got p'tits dessous inserts and a bunch of easy peasy hemps which I don't see how else I could use since all my other nappies are pretty much taken care of insert/booster-wise) so not really keen on selling them, but I can't have them hurting my bubba either, it kinda beats the purpose, doesn't it?

Errr... Help?

Eek, it's a pain when this happens isn't it, especially when you think you have the absorbency sorted! I hope your LOs legs are better soon.

If it were me, I'd try again in a few days once the redness has settled, putting it on a bit looser. That way, if you do it in the day too, you can see if it was due to the tightness or down to a reaction to the material round the legs.

Thanks, hon, this is great advice.

I think the red marks can be quite common with a tighter fitting nappy for that length of time so i'd loosen it as well and see how it goes during the day when you can keep an eye on it xx