Stepdaughter (10f) speaks only in whispers to me

Her mother (27f) and I (32m) have been together for three and a half years and lived together the three of us for two. She has full custody of her only daughter (E, 10f) who spends every other weekend with her dad and has an every other Thursday visit with her dad at our small 2 bedroom apartment. They always spend the entire time out to eat. We live in a major city, he lives an hour away in the country.E's parents were never married and only dated until E the as about 3 or 4 years old. They used to live about 25 mins away from her father. He lives on a few acres of family land in the forest in a trailer given by his mother. There are three other trailers there occupied by his sister, other cousins etc. It's only a little trashy, grandma smokes in her trailer and there are some broken cars n equipment around, but it's clean and safe and seems fine and kinda fun for children. E has similarly aged cousins there to play with.Her dad is a bit odd, my age, seems very intelligent but is kinda unambitious. He has another son and who doesn't live with him. He works a lot, often during his weekends, however he recently switched to weekday work. It seems like he dislikes me, I can't get him to talk to me and he's always giving me the most awkwardly aggressive handshakes. My gf and I joke about him but absolutely never around E. I frequently tell her how great it is that she sees her dad and that he's a good man.Since I've met E she's always been very quiet and reserved. It seems like more than just shyness, she basically only whispers and barely makes eye contact with me. Sometimes with her mother E is slightly louder and a tad more talkative and engaged, but only sometimes and this is still the exception to the rule. One time when E met my mother, mom said E seemed drugged because she seemed totally disconnected and avoidant. That seems an extreme statement but I get where she was coming from. E does not talk to or look at grown people or even my 5 year old niece.Her teachers have told us she's incredibly resistant to speaking in class and definitely in front of class. She infrequently asks questions and the teachers have given up getting her to speak at a conversational volume so long as they can get her to talk at all. She seems to struggle with math and often can't or won't tell us about her school work. She brought home a paper about a science project and it seems like she had never heard of it before. It's 4th grade science, it's literally the only thing they would be talking about in class.She says she has made a friend in her grade, she's been at her new school for 3 semesters now. They don't spend much time together outta school even though we can walk 4 or 5 blocks to their house. They don't seem like friends to me, at least not how I think little girls are friends with each other.I can see her mom gets frustrated and stern towards her about her quietness sometimes. Her mom has a tendency in my opinion to get upset or angry when dealing with problems in general. It's not a big thing, but I've seen it towards E too. I've told her how inappropriate that is and ultimately self defeating. She's gotten a whole lot better as we've lived together.I know she's not technically my step daughter but that's how I feel and is the responsibility I'm trying to accept. Her mom and I are gonna marry in the next 12, 18 months and we both want to have a few more kids. I love children, I'm good with them. Not E though. I have no idea how to connect with her or play with her. I'm super patient and kind and unflappable emotionally towards her. I take her to school and back, help with homework, I make her ride bikes with me outside, things I think a kid needs from a dad.I'm becoming real concerned. I feel like we have no relationship. She won't talk to me at all but two or three word answers and it's not audible. I literally have to put my head down next to hers to hear her even after I ask if she'll speak with me louder. It's making it really hard for me to like her. That's terrible I know but I know I don't feel the love a parent should and I'm assuming a stepparent should to some degree.She's not a little kid anymore, and though she's super well behaved soon she'll be a teenager and I'm scared she's going to completely not accept me as a parent figure or authority to be respected. Worse, I just want her to like me you know? She seems bored and unhappy a lot. She's been getting a little moodier lately.Please any advice or criticism would be welcome. I'm not the warmest or most loving person, but we have no affection or anything together and it's weird. via /r/Parenting https://ift.tt/2tF9SnX