Hakek asks:
If a girl does not have a hymen but never had sexual relations is she believed and considered to be besulah?
Hakek
The Kollel replies:
She is considered to be a besulah. The presence of a hymen is only expected for a girl under 12 years and a half. (not yet a "bogeres" - see Kesubos top 36b).
KOL TUV
Dovid Bloom