Mahrams

Second husband being a mahram for the wife's daughter

Q: I am getting married to a woman who already has a daughter, from a previous marriage. Would I be a Mahram for this girl, because Allah says:

وربائبكم اللاتي في حجوركم من نسائكم اللاتي دخلتم بهن فإن لم تكونوا دخلتم بهن فلا جناح عليكم

Would it be ok for me to travel with this girl?