Shall I leave my humidity dome on? N does she look...

Seedlings DO NOT need humidity domes! This is an outdated idea from 100 years ago.

what is ambient RH? if it's incredibly arid in your area, a dome may help. VPD matters so you'd want a temp and RH that jive together. Early on VPD should be a bit lower. I've read around .8 VPD, but seen different sugestions. I don'dt think there's real solid numbers to go by that truly represent the variety of genetics possible. Try to think of these two (temp and rh) as a dynamic duo and not separately except in specific contexts -- e.g. you don't want to be over 65% for a long period of time.. early on for clones or similar special situations is fine, but it's a disease a vector long-term. Nor being below 30% RH for similar long-term negative effects. The normal growing temperatures will keep you somewhere within 40-70% more times than not. Stage of life does matter. You can google for the wide range of suggestions. picture is a bit over-exposed. something on the 1 cotyledon? if it's a leftover membrane from seed packing, slide it off. make sure those leaves are ufettered and can open up properly on their own.

Does not look ok, give it air. no RH domes, they don't need em unless your operating in an area with average 30% RH. even then. cut the top off so its like a tube and air can still move aorund.

Humidity domes aren't as crucial for seedlings as it is for clone cuttings. High humidity is useful for suppressing transpiration but seedlings aren't really doing much of that anyway. Unless the RH where you got them is particularly dry(under 30%) I wouldn't worry about the dome.