I discovered Edenborough Evans on Facebook some time ago. My pick for Mother’s Day is their personalised silver necklace for $79.
I have two bracelets (they’re $59) and one has my (future) wedding date on it, while the other says ‘Be Nice’ but you can have whatever you want up to 8 characters (just enough for supermum?). Or buy her a gift voucher so she can choose her own.