It is a "Ladybird" beetle, one of the gardeners best friends. They are "predator" insects that eat bad bugs. No need to worry and just because there is one in your garden does not mean there is a problem, they fly around looking for food and that is all she is doing. Unless their are many more arriving, there is no problem. After this one has a look around for bugs to eat, as long as she does not find many, she will fly away and look elsewhere for bugs to eat. I think they are a lucky sign - that your garden is healthy and worthy of being checked over by this beautiful creature.
One other thing, please remove the bottle that is covering your seedling, cannabis does not need high humidity, but does need access to fresh air.
Leaving her under the cover can lead to fungal diseases and can also cause weak stems due to not having air movement to build her strength.
Hope this helps,.......
Organoman.