We went to Blenheim two years ago and it truly was fabulous. For you, it will be a full day trip with no time for the Cotswolds. But, it's worth it. We were in a car. If you are taking a bus which goes just to the palace gates, it is a very long walk and likely too much for your mom. I'm not sure how you will get from the gates to the palace entrance. As far as the interior sites, the Churchill exhibit is wonderful and I'm sure your mom will like it. The next item is a guided tour through some of the furnished rooms. Again, this is worth it as the guides are engaging. Third, we loved the upstairs tour exhibit/activity and it might be new since a previous poster has been there. Upstairs you take a tour narrated by a virtual, ghostly maid. She tells wonderful stories about the building of the palace and life inside. You go through several scenes with this virtual hostess. It's very clever and funny. Then there are the displays at the end that the previous poster mentioned as being somewhat boring. They are. We skipped past them and went walking in the beautiful gardens, which are extensive. However, the sculptured garden and waterfalls are very close to the house and you would feel fulfilled just by seeing those if you don't want to walk out to the Rose Garden (which might not be blooming in March anyway). We loved Blenheim and it is worth the effort to get there.