Im here, on the other side ladies.
I am a woman well into my 40s. I used to insist people call me by a man's name as a small child and growing up for a bit. I was raised in a very churchy midwest town, only child. The Thought of transitioning, then, in that area, was well kept out by church and lack of internet for us younguns. I barely knew what gay was, mostly from all the folk who called me butch and tomboy, got me curious to find out. Learned about cross-dressing but didn't realize there could be more than my jeans n tees already. Cried so hard the day I woke up with boobs as a teen, late bloomer and thought I'd be spared. And yeah, if I could have been a dude, I'd be a hella gay one. Was very confusing growing up with all nuclear family ideals and not fitting any of them, including their idea of the variety of the gender and sexuality spectrum that "wasn't allowed".
I also wonder if we had the internet media tech, medical knowledge and availability earlier, or was born later, who I might be.
I am afab, have similar ace feelings, got dates easier because afab and guys are horny, didn't always last long or end well, 'cause guys are horny and took offense to, no I don't care for sexy times please (at least it was common for me though teens n 20s). Have bffs that have lasted decades! Guys and girls. I am in a relationship now, have been for quite a long time, we are great friends at the base of our relationship and he is cool that I am not sexual most of the time (me as sexual, not his acceptance).
My bffs are just as important to me, the elated feeling when I see them, can't get enough time with them, feel so able to be my dorky self when we are together... boys came and went for a long time for me, friends stayed steady. With guys they call them bromances I think?
For me, a good best friend IS a relationship, that I liked better than romantic ones and I think it was because of the lack of sexual pressure that made it more comfortable for me.
So, no, not weird. When you don't have a handful of relationships, the one close one tends to mean soo much more. It is super hard to make friends when odd, especially as an adult. You mentioned she had one other friend at work, maybe they have similar interests since she likes them? Maybe you could try to get to know them too and have a 3 musketeers thing at work? They might not be near as cool and interesting, or bring the same feelings but it could help the emotional flows have another outlet. And, maybe they will know a couple cool peeps that could lead to another awesome connection with someone they know. This is how I usually got more friends as my friends were usually more outgoing than me. They know I use them for socializing and don't mind, part of what makes them precious to me.
Do be careful, emotions can come on strong sometimes and if she is happily married, a rise in romantic or sexual tension may be a push away and that can feel devastating.
I wish I had some better actual answers for you, hopefully someone's suggestions will be helpful though! People generally suck but there diamonds in the rough scattered about. You already have found 2, I am sure you can dig up more, it may just take a lot of time and patience to get the next one uncovered.