I would suggest introducing some white noise in your older dd's room, maybe some rain noise or put a fan on or something. It's easy to learn to sleep through something like this easily and blocks out all manner of noises from outside the room. Also easier to manage than ear plug faff! Loads of apps for white noise or background noise - I use relax melodies which has 96 to choose from! Dd2 listens to rain to cut out noise of DD1 playing with her cymbals during the day
Have you tried getting normal foam earplugs like these and cutting them down into mini ones with a pair of scissors? They probably won't block out teething screams though, they are better at muffling general background noise than sudden sharp/loud sounds. I sleep with earplugs and have never slept through the alarm with them in. Are they sharing a room?
Hi - my dd 4 year old has alwys been a light sleeper and so when dd sibiling was born 15 months ago we tried all sorts of ear plugs rexommeneded online - sponge bob pants foam, soft silicone all pf them seem to big and useless for her little ears and dont seem to block out the 15 months teething screams. reluctant to use cotton wool as I dont want it to get stuck in ear canal can anyone suggest anything else?