1983 10k yellow gold class ring

My mother in law’s. She’s worn it a lot but she’s getting angry because it’s getting too tight 😏 Dated 1983. It is 10k yellow gold. Has a Capricorn on one side and a Blackhawk (school mascot) on the other. Garnet stone. She doesn’t know if the stone is genuine but she is certain it’s 10k gold. It’s got her initials engraved inside. She got it from Jostens. She can’t remember what size it is but pretty sure it’s either 5.5 or 6. 🤷🏼‍♀️ 1983 is on it. Says Fennville High. Fennville Michigan. Mild discoloration inside. Needs to be cleaned. Some wear from wearing it. The garnet has a couple very tiny dings on it.