This vintage G1  mommy or mummy charm is Sweetheart. She's light pink with dark pink hair and a pink heart with an arrow through it for her symbol.

The  were originally available in  of the My Little Pony line in specially marked My Little Pony packages. There were 20 different charms to collect and they could attach to a charm bracelet available separately through a .

There's some discoloration in various places, mostly on the back and bottom of the charm, as shown in the photos. 

The pony is flat on the bottom and is marked "1984 Hasbro."

Measurements:

Height: 1 inch (2.5 cm)