Battling Christmas Plans: NM's use of guilt and intimidation

My mother announced last year, half way into November, that she wanted to visit in the three weekends before Christmas.  She stated the first week was out, as she was going on vacation.  She then stated that she would decide last minute between the next two weekends, depending on the weather conditions. It annoyed me that she wanted to hold us hostage to her whims. Why couldn't she just pick a weekend.  This is an extremely busy time of year for us. But I said none of that. I did tell her that we did have a lot of things going on in those two weeks.  My niece was having her second birthday party, my nephew was set to be born around the same time, in addition to the usually press of holiday parties, work functions, shopping, and our own little family traditions I squeeze in.  In the following weeks, the drama was overwhelming. I received phone calls and emails and texts, lamenting the weather and updating me on every storm that might come.  I repeatedly tried to pin her down on a weekend, as we had other family and friends asking to make plans with us.  No, she couldn't make plans.  No, she didn't know when she was coming.  Stressed, I finally informed her that although she was welcome to come, we did have things we had to commit to.  She became increasingly dramatic.  As it turned out, my nephew was born the first weekend in December.  My husband's family was all in town.  This pushed my niece's birthday to the second weekend in December.  I called mom to let her know.  "Well, I guess that will be alright.  It's only for the evening".  She stated, implying it wouldn't impose on her too much.  I told her no, it would be in the afternoon on Saturday, so most of Saturday we would be busy.  I wasn't trying to push her off, but these events were out of my control, and I really couldn't drop them all to accommodate my mother who STILL wouldn't commit.  As the second weekend in December approached, and she still was drawing out the dramatics of when to come, and the snow, and the horrible roads (and let it be said, I've traveled these roads most Christmas' to her house). I suggested that maybe it would be best to wait until New Year's weekend.  This infuriated her.  She became cold and unresponsive.  I talked to her several more times over the next few weeks, and although she didn't come on New Year's, I assumed it was over.  I actually felt good about setting some boundries.  Then in a phone call in January, it all came out.  While discussing my sister, she stated "I've done a lot of soul searching and I've decided that I need to make myself happy, even if my kids don't care about me".  I was FLOORED.  I lost it.  First off, we weren't even discussing me.  And I never told her she couldn't come.  I simple suggested she come after the dreaded "bad roads" were over, when we could give her more time.  She pouted and whined and said how important it was for her to see my son at Christmas time now that her mother had died and the holidays were so hard.  (For the record, she never really liked my grandmother.  They had a distant relationship at best.  Grandma had died two years before and her death only came up when mom was needing attention).  She couldn't believe I'd be so cruel, but she accepted she wouldn't make it up to see us until my second child was born (this was January; the baby was due in June).  I told her that would be just fine with me.  And hung up the phone.