If you're in the
UK, the name comes from St Olave, name of a former parish in Southwark, a village in Norfolk and several dedicated churches across the country. St Olave is actually an archaic spelling for St
Olaf, but Olave has a long history of use on females here, probably because of its feminine-looking ending and similarity to
Olive. So it could be considered (in the
UK at least) as a female version of
Olaf, which with the same meaning - 'ancestor's descendant' - would make a nice middle name for someone being named after her great-grandmother.
Other bearers: Lady Baden Powell, wife of the founder of the
Scout movement, was an Olave:
https://en.wikipedia.org/wiki/Olave_Baden-Powell