I can't stand my boyfriend's niece (11F)

I (22F) and my boyfriend (24M) have been in a relationship for 5 years. I started interacting with his family about a year into our relationship. Everything was going well. He lives with his father, his two siblings, Katy and Richard, and his niece (Katy's daughter), who at that time, when I was integrating into the family, was 7 years old. I tried to get along with everyone, including her. I did things like playing with her or letting her use my phone.

That’s when I started going on trips with his family to their country house, and they also included me in family activities like going out to eat, birthdays, etc.

I’m not sure exactly when it all started, but before I knew it, I was witnessing the tantrums, manipulations, stubbornness, and whims of his niece. My boyfriend is her favorite uncle, and she started being jealous of me. As I mentioned earlier, I don’t remember when I first noticed this behavior.

In short, if he takes a photo with me, she wants a photo with him. If he gives me a bike ride, she wants a bike ride with him. She’s complained to my boyfriend about why he does things with me and not with her, and she has cried (intensely) several times in public places for him to go be with her or do something she wants. In any public place we are, she throws these tantrums, crying a lot for him to be with her.

I told my boyfriend I didn’t like this behavior from the moment I noticed it, but he always said "she’s just a little girl," and would go and do whatever she wanted.

However, in these four years, she’s now 11, and the situation hasn’t changed. She still gets jealous of me, and continues crying in public places.

Recently, we went to a restaurant, and she cried because he sat next to me and not next to her. He pulled her aside to explain that I am his girlfriend and that he has to sit with me, but then she cried even more after he said this. Needless to say, she made everyone at the table uncomfortable. Finally, my mother-in-law gave up her seat so that she could sit directly in front of him, and she calmed down.

Then, while we were walking, she insisted on walking next to him, sometimes walking just a few centimeters in front of me to stay next to him.

Later, we went to a Christmas village. After we got out of the car, she stood next to him so that I had no space to hold his hand. My boyfriend let her walk ahead, then reached for my hand, but she got upset because he didn’t reciprocate her gesture. We walked a few more meters, and she disappeared from everyone’s sight due to her jealousy and anger. We searched for her all over the park, and my mother-in-law found her, of course, she ruined the night again. After the Christmas village, we got back to my boyfriend’s house, and he told me it was lucky that she wasn’t his daughter.

Also, I don’t like that she asks my boyfriend for money and demands it. Fortunately, he no longer gives in to her demands or tantrums. Now, he recognizes that she is intense and doesn’t deserve special treatment.

Her parents? Her dad is in another country but isn’t very present. Her mom is the one who raises her, but she never tells her anything or disciplines her. She’s a bad mother in terms of education, as I’ve seen this girl being rude to all the adults around her. Her maternal grandparents have been the ones supporting this child, so the real parental figure seems to be her maternal grandfather.

I asked my boyfriend to talk to his sister (not with the intention of reaching an agreement) but so that she knows what he thinks. Here are the points I think he should mention to her:

It’s overwhelming that she always wants to be on top of me and my boyfriend; we need space as a couple. I didn’t like when you suggested she sit between us that time; you should’ve handled it differently. Don’t suggest putting her between me and OP… we are a couple without children, and we would only allow that if it was our own child. I don’t like her asking me for money and demanding it. I don’t like her crying during family gatherings just because I’m not doing what she wants. I don’t like her complaining about why I do things with OP and not with her. I don’t like her being jealous of OP. I don’t like you thinking I have the responsibility to give gifts or money to your daughter; I’ll give her something when I feel like it.