To celebrate all that your Mother has done for you should certainly not be a one day a year kind of thing, but to take a little extra care in letting her know how much she means to you is definitely a good thing. That doesn't have to mean buying her something, take a long meandering walk with her, truly listening to what is going on in her life. Make her dinner. Tell her exactly what she has meant to you. If a token is something you would like to share, make it well thought out and something she can cherish.