1) Can I be made redundant while 35 weeks pregnant?
Yes. But as you say the process hasn't started yet. Usually takes several weeks.
2) Can I start my maternity leave earlier? Maybe from week 36?
Yes
3) How long does a redundancy process take and how might it be different for pregnant women?
It varies depending on how many people are at risk. If less than 20 it could take a few weeks of consultation before decisions are made. If more then it will be at least a month to three months.
It's not different for pregnant women.
It is however different for women in maternity leave. If you are on mat leave you must be offered any suitable vacancies, on not worse terms and conditions, before other applicants, even if they are more qualified. You should be offered the role without having to interview or compete for it.
4) What is the best course of action now?
I'd stop for mat leave asap to ensure you get the extra legal protection it offers. And to get you away from the stress. Ensure they have all your contact details and tell them you want to be kept fully informed. Remind them of your right to be kept apprised of what is going on and if any suitable vacancies to be offered to you.
5) Any other advice?
If in any doubt call ACAS