First of all, I prefer the term "extra mom" as opposed to step mom. I have one that I didn't get along with for a while, but now we are very close. My son also has an extra mom. So here's my advice.
I love that term! So much more positive than step parent! We call it special friend or she says best friend.
1. Never talk badly about the other parent. Ever. Don't let the child do it, either. It's one thing if they have a complaint that needs to be heard, but general badmouthing isn't tolerated.
I honestly try my best. Brooke can't spell well yet so if Josh and I have to have a discussion or talk about her mother we spell most of it.
2. Communicate frequently with the other parent. Agree to some rules that must be followed regardless of where the child is, and which rules or procedures aren't as important at one location or another.
As much as I don't care for her, I do try to keep in close contact with her mother. We agree on many things, and disagree on even more, haha, but we both support each other as co-parents in Brookes like.
3. Be supportive of the child. Give her plenty of praise when she earns it. The key here is to praise behavior and effort, not natural talent or physical characteristics. Example: She brings home a good grade. Tell her you're proud that she must have worked so hard as opposed to saying that she's so smart.
I do my best to encourage her to work and learn. If she does good at tball, I tell her good work. If she learns to spell a new word, I tell her she is a great learner and will be spelling everything soon. Right now we are working on distinguishing coins and using their names.
4. If you are having a disagreement with the other parent, or with your SO, settle it away from the child. Don't be afraid to stand up for her if you feel she's being treated unfairly. But also choose your battles. I promise, there will be plenty even among the best co-parenting units.
Always try to keep any parental negativity away from Brooke. Sometimes it isnt entirely possible, but we all work on it.
5. Make sure you treat the child in a way that is age appropriate, and have open discussions on all kinds of issues. Help her learn to think for herself.
I strive to teach her to be more independent and self sufficient. I encourage her to do things for herself and to judge herself for the things she does. She is so pampered and used to everyone catering to her, I feel it puts her at a severe disadvantage. Especially since she is starting school this year.
6. Read to or with her. (That always comes up in any parenting advice I give, because I think it's so important.)
Stories every night at bedtime! And we randomly practice spelling words as they come up in conversations. We learned red yesterday. We are working on pink now. She loves to color.
7. Show affection frequently, without pushing for affection in return. This is actually a problem I had with the ex, not the extra mom.
Our thing is snuggle time in the mornings. She comes into our bed when she wakes up in the morning and we sleepy cuddle. Silly girl likes to pet my head. Lol I didnt say the L word to her until she said it randomly one night when we were out eating, I almost cried it was so sweet and out of the blue. Now I always tell her how much I love her and how special she is in my life. It melts my heart when she tells me she loves me. But I don't fish for it, I want her to say what she feels, not what she thinks will make me happy.
I think you're off to a wonderful start. Just knowing you care about her is a huge deal in her life. My hat's off to you.