Mirror Mirror (1995) - Season 1, Episode 13.

When Jo Tiegan is given an oval-shaped mirror, as a gift, by the elderly owner of an antique shop, she is amazed to see another girl's image in the mirror instead of her own reflection. Jo (from the 1990's) and Louisa Iredale (from 1919) accidentally find that they can also travel to each other's times through the mirror.

Mirror, Mirror is a 20 episode teen television series, produced in 1995. The series is an Australian and New Zealand co-production.