I show my mother Hathaway and she never watched any gundam movie or tv show and she really loved and had no problem to understand what is happening.

As a better entry point I would recommand Witch from Mercury which is the lastest TV show

Despite what somes says here, yes you can watch without watching anything previously, there are some reference you wouldn't get but that it.

I guess you cannot watch this one without knowledge about Gundam. You need to know at least about civil war and the role of Hathway-senior in it... Otherwise you can enjoy mecha battles scenes but you will lose a plot.

It should honestly be fine, it's a pretty standalone entry in the Gundam UC timeline. Though the idea of seeing Hathaway without having watched Gundam 0079, or Char's Counterattack is interesting.

Hopefully it will make you want to go back and enjoy the other Universal Century shows. They're all available on Crunchyroll, and Char's Counterattack is on Netflix.

Can you watch it with no context, mostly yea, but you miss out on some of the motives. Mainly Hathaway, on why they are on this mission

A lot of the stuff in the Universal Century (UC) timeline of Gundam will make a lot more sense if you've seen the first three shows and movie:

Mobile Suit Gundam (some people will recommend the compilation movies - the show is much better imo)

Mobile Suit Zeta Gundam

Mobile Suit Gundam ZZ (some people recommend skipping this one - they're wrong)

Mobile Suit Gundam: Char's Counterattack

The Hathaway movies serve as a direct sequel to Char's Counterattack (they're based on a novel written by the series original creator), and CCA builds on events in the three TV anime preceding it. I know it's hard to recommend ~150 episodes of a cartoon and a different movie, but you'll probably enjoy the Hathaway movie more.

If you do the homework or not, it's a pretty cool movie with some good visual set pieces. Enjoy!