I, personally, don’t think that falling asleep would be a bad thing. I thought that meditation is to relax not only the mind but also the body. Therefore, if you’re falling asleep, I would think that you’re relaxed. I also could be way off base with my thought process. I’m no expert.
No that is not OK meditation helps us keep our thoughts, conscious, subconscious mind clear and also it helps in giving our body the more than needed oxygen so it performs well and at ease atleast for 10-15 mins. So if u fall asleep while meditating then that just means u r not meditating.