Am I overreacting...

Please let me know if I'm overreacting..... So just for some background. I've been married for a little less than a year with my first baby on the way. This is my husbands second marriage. Before he met me he was in two serious relationships after his divorce. He has a daughter from his first marriage, she is now 9. They divorced when she was a baby. My SD met and lived with my husband and one of his serious relationships.... Let's call her "Anna." My SD became very close to "anna" while they were together. Things ended when she cheated on my husband, otherwise they probably would have gotten married. After their breakup she began doing drugs, has posted nude on the web and from what I have heard from mutual friends has simply not been a good person or role model. She even slept with her best friends husband. That was 4 years ago when they broke up when my step daughter was five. Since then, "Anna" became friends with my husbands ex wife and for the past several years his ex wife has allowed and fostered a relationship between my step daughter and "Anna." About a year and half ago we found out that my SD had hung out with "Anna" after she had been drinking at the bar(in the morning no less). So basically she was drinking and driving with my SD in the car. We taked to police and they said there is nothing they can do since we found out after the fact. My SD's mom claims "Anna" wasn't drinking. My husband has asked his ex repeatedly to not let my SD see "Ann".
So here is my question.... Yesterday we called my SD and she kept declining the call. Come to find out, she was with "Anna." Again, my husband had a fight with his ex wife about it. Am I (or we I guess) overracting that this relationship has continued. What would you do? TIA