Offer her membership to a museum or may be a club or a historical society
. Stuff made out of silver is also a great option & quite affordable. You can also go for a good novel autographed by her favorite writer. Few more things that can help you in finding a perfect Christmas presents for mum is you need to note it down when ever your mum mentions that she might like it. This will always help you out when the time of buying gift for her comes around. If she collects something then you always have an option to add up to the collection. Family photos are always a happening option that can be included in Xmas gifts for her. Last but not the least, you need to remember that above all these stuffs she needs something that only you can give her, that's your time. She will always love to spend time with her lovely kids like you.