I am handfeeding a cockatiel from the day he hatched- he is now 15 days old. Incubation for lovebirds is 22-25 days then the eggs will hatch in a few days..I have mated pair of lovebirds I expect to start laying soon! yay!! This site may have alot of info your looking for - https://www.cuteness.com/article/incubate-lovebird-egg..... hope it helps.
She didn't even sit on them for the past few days. Also we live in a flat. The air conditioner is p good. But I switch it to 29-31 for them. It's been warm actually. Maybe they didn't hatch cuz it's their first batch