I personally have and love this little notebook, which features a spot for recording one line about the day's events for every day of the year. Next to each date are five lines, so through the years she can have a fun side-by-side comparison of her experiences. Your mom's first entry? "Got the best gift ever" on May 10, 2020.
Check out BuzzFeed's full One Line A Day journal review.
Promising review: "This is perfect! As a busy mom, I don't have time to journal extensively every day. This little book stays on my nightstand and gives me just enough room to jot down a few things from the day. It's a great way to remember funny things my toddler said, what the weather was like, or what activities we did during the day. I can't wait till next year, when I can compare from day to day!" —Megan
Get it from Amazon for $15.26 or from Bookshop (to support local booksellers) for $15.59.