This might sound like a daft question, what is she wearing to ride in. A decent pair of padded cycling shorts (worn without underwear, no offence to your gf but if she is a new rider, she may not realise that its far comfier, less chance of chafing and less seems to add to the pressure!), adjustments to ride position and finding a saddle (try looking for womens specific one) that suits should be what sorts this.
Personally, and it is a personal thing, I like Selle Italia saddles, but lots of others may not. Also, I don’t like chamois cream, except for long road rides. Its a case of trial and error but hope she finds something soon!