I Like Her, How To Act

Hi, first I want to ask the editors to publish my story because I'm a little desperate. So I will drive straight. I like a girl who is 12 (I am 13). We write with the girl in question all night, but we sit outside and are silent, we are just both very shy. I have a feeling she likes me too, but I'm not sure. 3 years ago she experienced something terrible - her father died after a work accident. When she shared this with me, she also told me that her best friend and I only knew about it. He also shared that he considers me a relative and trusts me. For me, this means a lot to me, because such things are shared only with really close people. My question is whether to propose to her now or to wait until we get closer. I'm just afraid he'll cut me off and end our friendship, or if we become boyfriends and something happens, which will separate us and make me lose a faithful friend. I am asking for advice