Okay, let's just give you the advice you want to hear...
You should tell her that you'll wait for her to get over her ex. Make sure that you don't sleep with any other women because that will be sure to upset her! If she returns to her ex, make sure you remind her that he's a very bad man. In fact, you should go out and buy her and her baby some nice things so you can prove your love to them, because as we all know, love conquers all.
Make sure you don't sleep with her within the first year of your new found love for each other. The last thing she needs is to have sex because there's a toddler to tend to, and she probably doesn't want to risk having another one just yet until she's sure.
You need to let her make all the decision in your life and in your future relationship. You need to keep her happy so you can prove that you're the perfect man for her, and you'll be able to show her how a lady should be treated!
Happy now?