flower

[bakermum4]

Stuck with last one as usual.
Musical instrument loses pot ash and gains backward account.
Thanks

[crofter]

The following is a bit of a long shot and depends on some of your clues being "a bit loose". Some setters have clues which are not as tight as they could be!

Firstly, Pot Ash is a compound with chemical name being Potassium Carbonate (KCO3). I believe that this setter (incorrectly) takes it to be the same as Potassium (K)

An ancient musical instrument is the REBECK.

AC stands for account ~ backward (CA)

Replace K in REBECK with CA gives REBECCA.

This is a girl's name, but is it a flower?

If nothing better turns up, I would go with REBECCA.