The top performance came in 2015 where she helped Austria earn a bronze medal at Golf Resort Kaskada in Kurin, Czech Republic.

She recorded multiple international victories, including at the 2015 Irish Women's Open Stroke Play Championship, where she posted a par on the first extra hole in a sudden-death playoff with Chloe Ryan at Dún Laoghaire Golf Club to secure the title, after both golfers finished the 54-hole event at 221.

[5] In 2018, Holpfer shot a 1-under 287 to capture the Slovenian Ladies Amateur in Livada, holding off Pia Babnik of Slovenia and fellow Austrian Emma Spitz by one stroke.

She wrapped up the 2018 season with a dominating 11-stroke win at the English Women's Strokeplay at Coventry Golf Club, where she led wire-to-wire after posting a 7-under 66 in the opening round and eventually finished at 13-under.

[7] Holpfer finished runner-up in her debut event on the LET Access Series, the 2019 VP Bank Ladies Open at Gams-Werdenberg Golf Club in Gams, Switzerland, where she lost a playoff to home player Elena Moosmann.