My mom, 1sis & I have had progressive hair loss in last 10-15yrs on top, crown & sides of head. Are we 3 females good candidates for hair transplants?

Check hormones first. Before you contemplate any costly interventions better if have a hormonal evaluation by dermatologist or endocrionogist to look into any possible medical causes of hair loss (such as thyroid, testosterone, iron, etc). Good luck.
Female Androgenic. Female androgenic hair loss is often hereditary and assuming this the cause of your hair loss there are several treatment options, including transplant that can fully restore your hair!