Housemate with Suspected Autism

Hi everyone,

I've come here seeking advice from anyone who can help. I'm currently in my third year at university studying Psychology and I'm also taking autism courses with the NAS to become a volunteer for young people with autism. I live with 4 other people and this year we have introduced a new housemate (Housemate X) meaning there are 5 of us in total (4 of us know each other already and Housemate X was a stranger before moving in). Since living with Housemate X, I have come to suspect very strongly that she has autism however I believe this is undiagnosed. The issues arising from her undiagnosed autism are affecting me and my other housemates and are causing a rift between us and Housemate X. While we all suspect she is autistic, we do not know how to tackle the issues at hand in the correct way because as I've mentioned above, she does not seem to be aware of any diagnosis. 

Our reasons for suspecting autism are:

• In conversations, she doesn't engage in small talk (e.g. if I ask how her day has been, she won't return the question)
• She seems to have set conversation topics (e.g. only talking about public transport problems)
• She is unable to engage in conversation about other people (e.g. all conversations resort back to her and often irrelevant links)
• She appears hyposensitive (e.g. going over a week without cleaning herself, wearing the same clothing item several times despite it smelling, not noticing foul smells from her kitchen cupboard, eating loudly with her mouth open, making random sounds, listening to videos extremely loudly, speaking loudly, not engaging in conversations unless name is said, frequently dropping things and difficulty knowing where her body is)
• Doesn't give eye contact at appropriate times
• Strong, nearly obsessive like for Strictly Come Dancing and some of the professional dancers on the show, I would describe Housemate X as a super fan.
• Her facial expressions don't seem to match her mood (e.g. we went out as a group and she later told us it was fun but her face did not show this at the time, she seemed angry and potentially upset)

Obviously, some of these signs are making it more difficult for us to engage with her and are leading to some bigger issues:

• Her uncleanliness is leading to foul smells that she does not appear to notice
• She doesn't engage in conversation so it's hard to create a relationship because conversations are always one-sided
• She makes completely irrelevant remarks which often end conversations
• She doesn't appear interested in getting to know us which makes forming a relationship hard
• She has problems with listening to us/our instructions (e.g. we have a cleaning rota and if not reminded she will not perform her chore, this week I did remind her and she still didn't carry out the chore; we had a maggot problem in our food bin after she had lived alone for a few weeks and we told her specifically how to clean it to eliminate the maggots but she ignored these instructions and the maggots returned instantly) 
• She eats with her mouth open and very loudly which is uncomfortable for the rest of us when we're in the same room

I'm really looking for advice on how to tackle the problems developing, considering the fact we believe it is undiagnosed which adds many further complications. Thanks for any help in advance, all advice is welcome. We don't want to push her out, we just want to help and find a way to include her where possible.