It's really amazing. You've both bean moaning about the lack of coverage for other marches yet you are both unable to provide an example to back up your claim. One of you tells me to "do my own research innit", and the other tells me yet more examples of marches that *have* been covered.
MRS Steve R, maybe you are one of the older fashioned ladies. Nothing wrong with that, but calling yourself Mrs Husband's Name is something that would have some feminists up in arms. Nothing wrong with that either, but the fact you are calling yourself Mrs Husband's name may mean that you are not tuned into the argument of the women who were marching.
In answer to your question, you won't lose ANY rights due to Trump being elected. As far as I can make out, he has been made President of the USA, and doesn't have any ability to change laws in the UK.
What do the women who were marching think they have lost? They have lost some equality. In the 70s and 80s it was more or less accepted that a boss smacking his female employee's arse, forcing her to wear certain clothing, paying her less than her male counterparts, giving her an unwanted shoulder massage etc etc.
Trump has, unwittingly, given the pervy boss a bit more "courage" to push the boundaries again. No, there won't be any changes in laws that take away American women's rights. The damage is more discreet than that.
Those women may think that Trump will set the women's movement back 20-30 years. They may be incorrect, but considering the battles that feminism has had to fight and win they have earned the right to defend themselves.