Do you think though...... if Marion was about to fly off to meet up with a lover/husband/new man, then her whole demeanour would have been different in the lead up to her leaving. She would have been excited and giddy - the Marion we have been introduced to loved to be in love - so this would have been really excited and bubbling about the trip
Instead Sally describes her as "exhausted" and how she chased Chris out of her house one evening when it appeared she did not want him to rumble anything about the new man. This does not sound like someone who was loved up and excited to be going on an adventure with a new love.
To me this sounds like someone with secrets and possibly not good ones
Why wouldn't Marion want her friends and family to know she was in love, off on a great adventure and happy, if indeed this was the case. Friends and family want good things for you generally don't they, so although they may have been surprised, they surely would have wished her well and wanted it all to be amazing for her! To hear regularly and be updated and go to the wedding (if there was one). Who marries, or pretends to marry someone that no one in their circle has met? And doesn't tell anyone? The secrets she kept were huge but we do not have any understanding of why?
I am imagining standing with all that luggage at the bus stop, with no one there with me, getting on a bus to somewhere that only I know where, to catch a flight to somewhere that only I know where. I have nothing material here - no house, no job, no car (its being sold), a container full of my belongings, which only I know where they are. I have a new name and a new passport that only I know about amongst my family and friends. After all my meticulous planning, the day has come and off I go.
How am I feeling? Trying to stand in her shoes, after having done all of these things with a plan in my head that I had not shared with anyone, I would be feeling one of two things -
Abandoned - how could no one see that I was struggling, where are they tonight? I am going away for a year, and there is no one here with me, gosh I got to 51 years old and there is no one who will rock up for me to see me off. Wow, that is sad. No one noticed all the things I did to shut down my life, and here I am, all alone. I hoped that somewhere along the way someone would notice and beg me to stay, but no, clearly I don't mean as much as I hoped to the people I care about. So I will be ok without them, I'm good. (and a giant FU) at the same time. Didn't need you anyway.
Or
Thank goodness that's over, I am free. Who knows what comes next, let's go! I am never coming back here, how exciting! I feel like a spy with all these secrets but look at me go! I pulled it off!
Of course these are just my interpretations of how she might have felt, but that is such a massive thing to do and there seems to have been little notice taken that she was making such a big trip - that is a big deal to do on your own (as it appeared). If your kid was going off backpacking for a year, you would have a going away party, or a bit of a send off. If you get the courage to do something later in life, this is even more out of your comfort zone, but there does not seem to have been any kind of "fanfare" deal of her leaving, party, family meal out, bon voyage all that, instead she cleared the decks, wrapped up her life and almost slunk away.
Please correct me if any of that interpretation is wrong, but if that was me I would be on that plane either really elated or in floods of tears. Either way, no one seems to have noticed.