Okay to start off I need to explain who I am and ...

I do not know this woman, so I cannot speculate as to her motivations and/or whether or not she was sincere in her offer.

What I CAN tell you is that she is an adult. And as such, she is capable of making decisions and determining when enough is enough and when something is 'too much.'

If she made the offer and you believed it was genuine, then I think you should feel free to take her up on it (I am presuming this IS just a mentoring relationship and NOT anything personal and/or illegal).

If she has changed her mind, she should be competent and intelligent enough to say so.

It is a wise person who learns, 'Don't say yes when you want to say no' and 'Nobody can take advantage of you unless you let them.'

Give her the benefit of the doubt - she is old enough to have learned those lessons long ago. If she hasn't, you'll soon find out.

Do not let the friendship go.  She is definately your friend as she would not have been as helpful in the past.  When you talk to her make sure any problems you are wanting to discuss are serious and not petty.  You are right about her needing her space when she has her babay but you two can still be friends.  Just don't encompass her every moment of life.  She has a  life also.  It is extremely hard to find good friends and it sounds to me that you have found one.  My question to you is this.  Is she your friend or are you in love with her?  Think about it!

During this time when she has her baby, try to be more giving and less taking ( of her time and attention). Give her a baby gift, send a card, but don't over whelm her with your personal problems for now. Try to ease off from that for a while.

I also had the feeling that maybe you have a crush on her. If that is true try to distance yourself from her and ease off the friendship gradually or completely.

Sorry, I didn't realize you are a girl. I thought it was a boy writing the question. I wish you the best for your life and I hope you get your problems straightened out. Good luck!

First I should tell you that I have taught in a high school, so you are getting a teacher's perspective.

There is nothing wrong with continuing to keep in touch with your former teacher. Nowadays with internet, it's easier than ever. 

If she didn't want to keep in touch with you, she wouldn't have said the things she did. Just don't overwhelm her with daily letters. Keep it to perhaps, once a week or so. When her baby is born, maybe you could sent an inexpensive gift of some sort. 

I'm sure she appreciates her connection with you.