There is a Maughold burial for a Margaret HARDY buried Jan 2 1815.

Could this be her? Or did she have children after this?

Brian Lawson's wills index has:
HARDY, Margaret 1815 Bride, Arch., [number] 71, LDS film no. 0106240.

The "Bride" is a bit confusing, but it would definitely be worth a look. If it is her will, and if she had small children, it will probably name her siblings as supervisors.
Perhaps they had moved to Bride where her daughter later married?

It would also be worth asking whether anyone has a MI for her in Maughold or elsewhere - "Hardy" wasn't a usual name in the IoM (unlike Christian!).

Sue