Can i donate my eggs to a family member if i only have 1 ovary, after a partial hysterectomy?

Yes: One ovary can produce eggs for long time.

Technically yes: If you have a functioning ovary, then technically you still have viable eggs. It is unlikely that a reproductive endocrinologist would recommend using eggs from a 40 year old due to the increased risk for genetic anomalies and the decreased likelihood of a successful transfer with the eggs fo that age. Since the eggs are as old as the donor, egg donors are usually much younger.