Abandoned nest?

My Muscovy was sitting on nest of about 8 eggs for 10 days non stop.... on day 10 she got up and now refuses to sit on them.... I’ve candled them and they appear to have veins but they are very faint..there is a large dark spot with a small darker spot in the middle of it..... she still covers them over and she “checks” on them occasionally but not sitting n them.... this morning when I let her out I noticed she had “kicked” 2 eggs out of the nest and had completely covered the rest... she’s only a young duck about 8-9 months old and this is her 1st clutch.... her sister is still sitting on her nest and so is my older female (3 ducks all nesting) papa duck also goes and “stands over” the nest that has been left.... any ideas or suggestions? Is this normal behaviour? It’s also been quite warm the last 2 days as we are in spring and warming up rapidly.... thanks