Mother's Day is a chance to do something a bit different for your Mum. People all over the country are taking their mothers out to lunch on this day, buying flowers etc - nothing wrong with that, but the best present is something that you know she would like.
If there is something you know your mum would like, whether it's something small like a book or DVD she wants, or something bigger - maybe a dress etc that she's admired but didn't think she should buy for herself - that would make an ideal present. If not, just go by her general tastes. Women around 40 often start to feel that it's not worth doing much about their appearance, especially if they are busy looking after families, so something frivolous like an item of jewellery or clothing can make her feel special again. Or you could get something personal, like having an album made up for her, or treat her to something a bit different from a meal out - like a spa day or a special trip.
You can find more ideas here.