Translation:Oni fydd hi?
Thanks for the comment.
This is a mistake, apologies for the confusion. It's now been corrected.
The full translation of 'Won't she?' = 'Onid fydd hi?' (literally 'Will she not?)
This is usually contracted to 'On'd fydd hi?' by dropping the 'i' to make it a shorter phrase.
Of course "On'd" looks very much like "Ond" but that is a completely different word and means 'But'
I hope this clarifies the situation.