Reintroducing cats

So my siblings and I moved out of our parents house and moved into two apartments in the same apartment building. my cat moved in about a year and a half after I moved. but my siblings cat stayed at my parents until about a month and a half ago. The cats saw each other was about a year ago when I brought her over to my parents house for a bit. My cat hissed at my siblings cat once when he tried to initiate play and she wasn't feeling it. They where still chill. and hung out together my cat is just not a fan of sudden play. but the last time they met was I admit pretty stressful. we brought him from our parents house to my apartment in his crate and my cat hissed at him quite a lot. we then gave him a bath and then loaded them both up to go to the vet. after the vet appointment she went to my apartment and he went to my siblings apartment. I would like for them to interact. we live on different floors but animals are allowed in the common rooms and we could meet at one of our apartments. I wanted them to get used to smelling each other so about 2 days ago I brought over my cat's blanket for him to sniff and his blanket for my cat to sniff. they seem chill with the blankets. they sniffed them quite thoroughly he seems to mostly ignore it after that and she is currently napping on his. I was wondering about when and how I should go about reintroducing them. my girl is a small and mostly gentle but easily disgruntled 8 pound floof ball and he is a muscular 17 pound short haired tuxedo who doesn't really communicate when he wants to start play but is typically really chill. my cat has been over to my siblings apartment before he moved in. they first got introduced when she has about two weeks old. she was a few days old when I took her in and bottle fed her. her mother didn't develop milk properly and then abandoned her. he seemed chill and curious and she hissing all over the place they later met when she was about a month and a half old and he seemed not to know how to play with her but was excited to be around her. he would tackle her and groom her which was the cutest thing. my cat doesn't really like as much contact as he does and wasn't as excited to be around him but liked to hang around him when he wasn't have trying to make her play with him. I hope I gave enough information.