Unlike guys who're ready to go once erect, women need foreplay. It's not optional as without it they wont self-lubricate their vagina and any attempt at penetration is going to be very uncomfortable.
Hymens generally begin to dissolve with puberty as estrogen begins being produced. I'd be very suprrised if her's is in anyway intact by 27. There's so much bad info out there about hymens and virginity it's no wonder people don't understand it. If a female lover of 27 is too tight, it's much more likely she simply isn't physically arroused yet.
That said, I have read of those who're literally too tight but not because of hymens or insufficient arrousal. These are just shaped that way and have very small diameters. Surgery to widen can be done as a last resort. But I'd try everything else first.
First have her mention it to her ob/gyn. See if it's a 'just shaped too small' or not. If not, try the same things you would for first time anal sex and start small, and over time (days or weeks) increase the size of the things used for peentration until it's comfortable. And be sure you're actually getting her arroused. Can't just kiss a few times then shove it in. Foreplay should be at least half an hour.