She wants to call me mom..

My significant other has an 8 year old daughter who has been through quite a lot.

Her mother abandoned her when she was 2-3 years old and signed over her rights to her. Both of them were 16 when she was born.

He then married when he turned 19. She spent all her time getting high and not being a proper parent. She wasnt the worst but she definitely caused his daughter a lot of emotional damage by being hard on her, not supportive, treating her younger than she should have been etc. Like I said she also spent literally every day high, she had his daughter help her steal etc. She began to emotional abuse her in order to manipulate her when they separated.

I've not been with him 6 months and they have lived with me 4 months. I've known him for 2 years and I know it seems we moved fast but we have many reasons behind our story.

I have kids of my own too. She loves me to death, tells me how thankful she is that I am the mom that I am. She tells me I feel like her mom and that she loves me. She recently started writing mom on things for me but still verbally calls me by my name.

Tonight she said "I'm not allowed to call you mom yet am I?" I asked her if that was what she wanted and she said "well, I feel like your my mom and I look at you that way".

Is it too soon? Do I tell her it is okay to call me whatever she wants or do we discourage it for now? Her dad is okay with it but I do not want it to be too soon for her.