Present Ideas?

I think as we get a little older, some of the best gifts one can give is spending time with that person on or around their Birthday. So, how about taking her to breakfast, brunch, lunch or dinner and stopping by her favorite book store and buying her present right on the spot.
You could also have a giftcard for a bookstore you know she loves and a bookmark in the card and present that to her at lunch, drinks...dinner whatever you decide to do together.

I just put together a teacher gift for my sons teacher and it turned out so stinking cute. I got an empty terra cotta planter, stuffed it with green florist styrofoam and then glued in some moss. I then attached gift cards to different places/things (I personally did a gift card to Barnes& Noble, iTunes, Target, & a local restaurant) onto skewer sticks I painted green and added my own leaves. Then tied bright ribbon around them and added a few more fake flowers to completely fill in the pot. I then tied a fat ribbon around the pot and hung a note that also included a package of seeds so she can re-use her pot. Good luck, I know you'll think of something adorable and personable!

Barnes & Noble gift card or amazon.com gift card?

A gift card and a pretty book mark.

Because life is so hectic sometimes, I just like to spend time with my friends. Get her a pair of cute flip flops and take her for a pedicure and lunch together. Maybe you could follow lunch with a wander around your local bookstore. Time really is the best present.

Amazon gift card

A gift basket of shower gels, towels

A basket of snacks, teas, Starbucks gift card for reading time.

Gift card to her favorite book store, Gift card to a great restaurant.

Tickets to a performance.

If she likes, mani, pedi or spa treatments, gift card for a half day or full day of spa treatments.

NO teacher stuff.. She has enough of that stuff and teachers get so tired of that "stuff"..

How about one of those booklets you can get that is about the year she was born? I've seen them at Borders bookstore.

Or see if you can order the front page of the newspaper in her hometown from the year she was born. I've heard people have done that in the past.

I agree with what others have said about the gift of time. I'm in my mid 40s and I cherish the time I get to spend with family and friends above anything materialistic (although I do enjoy receiving things as gifts :-)
If she is your friend first first and a teacher second then her occupation really has nothing to do with who she is as a friend.
Does she enjoy wine? Maybe you could take her on a 1 day mini wine-tasting trip. You could go to a couple of local wineries and taste and possibly even buy some wines.
If she likes books try finding a used book store and take her there and let her pick out a couple of books then go take her to lunch and spend time really getting to know her.