When Lovebirds get plucked by their parents it's generally on the head, back of the neck and shoulders. I've never seen parents selectively target only flights and tailfeathers. Even if one of my birds were to go for anothers flights, they're not a clean cut like that, they're bent or twisted. Someone butchered those babies.
I had to go back and look at your posts...
on 1/13 you mentioned getting a Fischer Lovebird, the Green Pied Opaline, and the two standard Peachfaced lovebirds.
on 3/6 you got the Cinnamonino.
and now on 3/11 you got the three Peachfaced Parblues.
How are all these birds doing? How are you housing all of them and what are your plans for all of them? These birds can live for 15 to 20 years.