Sometimes it is hard to 100% discipline my SDs. I have the blessings of DH and BM but, they don't get it. There are certain boundaries you cannot cross. I am NOT the parent or relative, for that matter. It's very frustrating at times.
There are also not a lot of women to ask. A Mom and Step Mom are different. A childless StepMom usually has childless friends who don't want to hear it (but yet are curious...I have someone at work who found my blog and reads it...how and why I do not know). Your friends with kids don't understand or make you feel worse about it.
To explain better, I am referring to a great sample article by StepMom Magazine (a really good positive online source!) to try to explain it.
If you are a SM, a CSM, know someone who is, or a Stepchild; read it!
Top 10 Reasons Why Becoming a StepMom is More Difficult Than Becoming a Mom