We talked at the party for quite awhile and it became apparent that we had a lot in common. She liked things that I did and vice versa. I don’t snow ski anymore, but she does and she owns a time share out west and ended up inviting me along with her next winter. I told her that before we go that far, why don’t we have dinner and share an evening learning about each other first and she did agree. Last night was our first date. When I got to her condo, she had her sister with her. When my date excused herself for a few minutes, her sister told me she was very nervous. This was her first date since her husband died and she told her sister she felt like she was cheating on him.
I was finding it a little difficult following the timeline, but anyway: Just wondering, for clarity. When meeting her for the first time at a birthday party, later at the same party she invited you to her time-share, to be planned next winter? It’s none of my business, were there others invited to the time-share for next winter too, or just you, someone she had only recently not met?
Were the three of you at her condo all that evening?
I was very careful what I said or added to her conversations. I thought it best to let her do most of the talking. When she asked about my past, I kept it short. We had finished a very nice dinner. I took her to one of D.C.’s finest restaurants that I enjoy, even though it is very costly, but you get the treatment you pay for. I had planned next to drive over to the MGM casino and they have either a special event (like Gladys Knight, etc.) or you can get a table, have drinks and listen to a live band. We had only been there about a half hour when said she wasn’t feeling well (I thought maybe she was wanting to ditch me) and would like to leave. No problem. I had the valet bring my vehicle to the front of the hotel and when we got to her condo, she invited me inside. I asked if she was sure she was up to having company and she said she felt better.
I wonder, did she have any part to play in the planning of the date, or was it left to you without any consultation with her. Did she not know where she was going until the date started?
Is it possible in her mind she might have thought there were too many distractions for a first date, and that’s why she wanted to leave for somewhere quieter? The only place she could think of at the time being her condo? Was her sister already at the condo?
She said she was very curious as to why I never married. She told me (and shocked me, which is hard to do) that to many ladies, I was walking gold. I was puzzled by what she meant, so I asked her. She said you don’t realize that men like you only come into a woman’s life maybe once in 50 years. You have your own home, are financially secure, have social status and are very good looking and what amazed her most was that I didn’t realize any of that.
Woman have said similar to me, even my own female cousins have, for which I have many. For me at least, I don’t think I would read too much into it. Why wouldn't a woman be curious as to why a man hasn't married, regardless as to whether the question was asked on a date nor not.
Her last words before kissing me on the cheek and saying good night was, “I don’t get it. There has to be more to your story.”

...

... What might that tell you? For some reason I can't stop smilling as I read through this.
Now, I am really puzzled by her assumptions of me.
I would't be puzzled.
Do I ask for a second date or were her parting words her parting words? I’m definitely confused.
Personally, I wouldn’t see that as her last parting words. i.e. “
I don’t get it. There has to be more to your story.”
I don’t think I would be confused by those words.
I thought of asking my friend to asker sister how things went on the date and would she be up for a second date, but then I thought, we’re not in high school anymore.
Asking a friend to ask my dates sister how things went would be something I would never do. I would call my date and ask her myself, but thats just me.
Give her a call on Monday evening and ask her if everything’s ok between us? She is the personal secretary of a Senator and works in the Capitol. Any thoughts?
I wouldn't use those words after only one date. I might ask her how she felt about the date, and tell her what I felt, in a positive way. I would
tell her that I would like to go on another date, and
ask if she would like that too, or something along those lines. Maybe she has her own ideas of what a next date should look like. That might not include expensive restaurants or a somewhat noisy atmosphere?
If you have any reservations regarding a next date, I'm sure she will pick up on that straight away, without you even telling her directly. But that’s just my initial thoughts, for what it’s worth.
Seems simple to me, call her, shes probably waiting for your call?