My faves would be, April &
Holly (probably my fave!)
Brooke
Elizabeth (but I prefer Elisabeth spelling)
Blythe
Grace
Daisy
Isabelle - but would spell Isabel or the Scottish Isobel with the tailored/non-fussy April.
I would not do a repeat A name, and I also don’t think Abby is substantial enough and could almost be misheard as a nickname for April.
Some combinations:
Holly Catherine
Holly Elizabeth
Holly Blythe
Brooke Evangeline
Brooke Marigold
Brooke Felicity
Elizabeth Hope
Elizabeth Honor
Elizabeth Grace
Blythe Catherine
Blythe Seraphine
Blythe Vivienne (or Vivien might be better flow)
Grace Elizabeth
Grace Vivienne
Grace Catherine
Daisy Constance
Daisy Catherine
Daisy Blythe
Isabel Catherine
Isabel Grace
Isabel Hope
Edit, some other names you might like: Verity, Tabitha, Imogen, Phoebe, Violet, Clara, Elise, Sylvie, Loretta, Seraphine.