These are difficult to combine without knowing what the first names are.
I second PP’s suggestion of [name_f]Shonna[/name_f] for [name_f]Sharon[/name_f] and [name_f]Donna[/name_f], and maybe [name_f]Kaitlyn[/name_f] for [name_u]Shannon[/name_u] and [name_f]Kathryn[/name_f]?
[name_f]Shanna[/name_f] ([name_u]Shannon[/name_u] and [name_f]Donna[/name_f]) also spelled [name_f]Sana[/name_f]/[name_f]Sanna[/name_f]
[name_u]Daryn[/name_u] or [name_f]Dora[/name_f] ([name_f]Donna[/name_f], [name_f]Kathryn[/name_f])
[name_f]Rhiannon[/name_f] ([name_f]Kathryn[/name_f], [name_u]Shannon[/name_u]) also spelled Ryanon
[name_f]Sharona[/name_f] was going to be one of my suggestions too!
Some other possiblities:
[name_f]Anais[/name_f]
[name_f]Anoushka[/name_f]
Arwyn ([name_f]Arwen[/name_f] means noble similar to [name_f]Donna[/name_f])
Bryonna ([name_f]Brianna[/name_f] is similar to [name_f]Donna[/name_f], y for [name_f]Kathryn[/name_f], and other sounds/letters for [name_u]Shanon[/name_u] and [name_f]Sharon[/name_f])
[name_f]Dyana[/name_f]
Doryn
[name_f]Grace[/name_f] (meaning of [name_f]Sharon[/name_f])
[name_f]Katriona[/name_f]/[name_f]Catriona[/name_f]
[name_f]Karis[/name_f]
[name_f]Karon[/name_f]
[name_f]Konstance[/name_f]
Odyle
[name_f]Norah[/name_f]
[name_f]Rosanna[/name_f]
[name_f]Rose[/name_f] (for [name_f]Rose[/name_f] of [name_f]Sharon[/name_f])
[name_f]Sandra[/name_f]
Sandryn
Shanton
[name_u]Shay[/name_u]
[name_u]Sky[/name_u]
Sydonie
If you don’t really want to use these, disappoint them all & choose your own name. You should [name_u]LOVE[/name_u] the name you choose, not just try to please other people. They’ll get over it.