Mycroft ships
In the beginning I was a bit reluctant to ship Mycroft with anyone at all (except possibly his umbrella?) since it seemed to go counter to his character, but after watching season 3-4 I felt like he started opening up. Especially after Lady Smallwood started going for him and he seemed half confused and half flattered about it I started entertaining the various possibilities.
Even if he seems to think this is the case, I don't think Mycroft could ever get proper understanding from someone who is just like him. I get this image of two people who sit isolated in different towers and don't have what it takes to bridge the gap even though their view on the world is the same? Hence he really does need to acquaint himself with some variety of goldfish if he wants a relationship at all.
This is not an exhaustive list of any sort. I included ships I wasn't into personally at first but I regretted it as I felt this was really unproductive. Better to only mention the positives.
Mollcroft (Mycroft Holmes/Molly Hooper)
While my brain says this ship has no validity in canon, my heart says there is so much potential and I love this ship. It might be because I love these characters individually and so I will gladly add a bunch of bias and wishful thinking.
They are both givers (Mycroft often does not take no for an answer though) who care deeply and I just want them to divert their attention away from their usual recipients for a bit so they get to experience some mutual care and understanding. Also I think Molly is empathetic and perceptive enough to read Mycroft's emotional states, even when he lacks the language or awareness to express himself. Also, she is freaking smart. Meanwhile Mycroft is reliable and won't be as likely to hurt her feelings with tactlessness. I see them as an odd pair coming together in odd ways, not the normal romantic path that is preferred by society but something else that suits them.
Smallcroft (Mycroft Holmes/Lady Alicia Smallwood)
My brain says this is pretty valid and Lady Smallwood shows that she cares and has made an effort to understand Mycroft, but my heart isn't entirely on board. She overall acts very supportive though and I appreciate that there is such a person in Mycroft's life. I really don't mind if they are romantic, but I'm not passionate about it either.
I notice a lot of complaints about the age gap but it's really not that significant. No one would think twice about it if the man was older.
Sometimes there is confusion about her name being Elizabeth, but when I watched the show it said Alicia when Magnussen read her and this matches the name on the card so I go with this.
