She had floppy eyelid when she fell asleep. is it something i should be worry?

Probably not: Not sure what you mean when you write 'floppy'. Did one eye close more than the other? If, when she is wide awake, both eyes look normal and symmetrical then I would not worry. If one eye is droopy she should see her GP.

? Sleep apnea: Floppy eye lids could associate with sleep apnea (lack of oxygenation during sleep when stop breathing momentary). If you snore and over weight the chance of sleep apnea is high. Do you feel tired and sleepy during the day ? Then that is also sign of sleep apnea. If your answer is yes for most of those questions you may have sleep apnea. Pls get sleep test and discusse it with your doc.