Mystery Couple

Mostly we get lots of really nice people into our store. Some not so nice, some weird and some just plain scary. We really enjoy having a chat when our regulars come in. Sometimes it's just about the weather and sometimes it turns into a deep discussion on the meaning of the book they are reading.
We have one couple (I'll call them Linda & Tom) that comes in about once a month. We rent the space above us to a hair salon/permanent makeup business. We noticed they started coming in after they would visit the salon.
This is a really nice couple. I have nothing but nice things to say about them, so do not take this the wrong way. I mean no disrespect at all.
Let me just say there was something different about them. We couldn't really nail it down at first. "Linda" is extremely soft spoken and can be very difficult to hear, but it's easy to get her to laugh. She is a rather tall big woman. Her partner, "Tom" is a short man who can be very nice, but you have to be careful. He can get grumpy fast if you say the wrong thing. You can tell that he is very protective of "Linda". Overall though very nice people. We soon figured out that "Linda" was a man. "Tom" we have not figured out yet. He might be a man from birth, but it's hard to tell.
Anyway, they are regular visitors who frequently come in and trade books. When we get books from people you would be amazed at the weird stuff that gets put inside them. Maybe I'll do a Thursday Thirteen on that next week...hmmm... Anyway one time inside one of their books we found a piece of paper from a psychologist. It was a form that explained that "Linda" was diagnosed with "Gender Identity Disorder". We immediately felt guilty for ever reading the paper as it was none of our business and threw it away.
We really like these people. They are so nice to us. They even brought us cookies one time. They really like the spooky decor of the store and will bring us things they find to add to the decor. The reason I bring all of this up is because it is a frequent conversation around the store on how we can treat these people as normally as possible. It's human nature to be curious and look a little too closely, but we don't want to make them uncomfortable. We want to treat them like every other customer that walks in the door. Unfortunately, I think we end up over doing it in the welcoming squeals we let out every time they come in. We just feel like it has to be so hard for them to go out in public and we want them to know that they are always welcome in our store. Does that sound weird? It can't be an easy life. People staring at you all of the time, whispering behind their backs. We just want them to know we do not care. That they are nice people. I realize I am talking behind their back right now, but not in a bad way. I just want to do the right thing and we often get confused on how to treat them without over doing it.
I'm not sure why I brought this up. We just feel very frustrated with ourselves sometimes. We want to be completely normal with them and we end up sounding like bumbling idiots. This is probably coming out all wrong. I'm not good at expressing myself obviously and I hope that we are doing the right thing. We just want them to feel comfortable.
Obviously this is just me babbling on and on. I'm not even sure what I am trying to say/ask, so I should probably shut up.
Cheers!