Toni Boone, 25, of Woodstock Avenue in Galashiels, also admitted stealing goods worth £62 from Boots in Galashiels on June 6.
A not-guilty plea to stealing a bank card from a house in Croft Street in Galashiels on May 25 was accepted by the crown.
Selkirk Sheriff Court was told Boone used the stolen card to obtain the voucher by contactless payment at Tesco on May 25.
Fraser Matheson, prosecuting, said a fortnight later at the Boots store at Gala Water Retail Park she put cosmetic items in her jacket and left without paying.
That theft was caught on CCTV, however, and the stolen goods were recovered.
Boone was fined £100 on each charge, to be paid at £10 a fortnight.