Is she asking too much?

You sound like a nice guy. You don't say what problems you guys were having, etc., so it's hard to get a grip on the situation. This lady has done you wrong and wants to keep you around while pushing her relationship, happiness, etc. in your face. You need to stop the emails until you find a place of indifference towards her. Your heart is broken and you need to heal. I'm sorry, but she doesn't sound very trustworthy, moral (different fathers for her children), or have good character. Be happy you didn't have a child with her, spend more of your life with her and got out when you did. Take some time to heal and then find a wonderful girl who wants you. Good luck.