The era and personality of the parents is very tricky to pin down. I can’t imagine the same people naming all three.
Susan is something that elegant, no-nonsense parents might have picked in the 50s/60s. Corrie’s parents might have had her in the late 70s, and would have been free spirits who didn’t always think things through.
Desirae is very 80s and has a slightly brazen, adult vibe.
If you want them to sound like sisters who are close in age, what about
Susan,
Corinne and
Diana (60s)
Sasha,
Corrie and
Demi (70s)
Shannon,
Courtney and
Desirae (80s)
Susannah,
Coralie and
Dahlia (current)