Do I "have" to include the "in-law"?

Today is my mother-in-law's birthday.

In honor of the day she was born (a certain # of years ago), 

I'll share 55 statements that make me think of her.  

(Why that amount?  Oh, no particular reason...  ;)

 1.  Talented Cook

2. Appreciator of Good Food

3. Cook Books, large collection of - and adding to it as we speak!

 4. Supporter

5. Hugger

6. Well-Dressed

7. Lipstick

 8. Fun-loving

9. Musical

10 . Gum

11. Constantly Learning 

12. Adventurous

 13. Patient

14. Selfless

15. Enduring

16. Ruthless at games
(She can try to deny it, but those that know her best know better!
She'd crawl over one of her grandchildren to get a wild card!)  

17. Floor-Dweller: always willing to get on their level and be with them
(especially if it gets her closer to that wild card...LOL)

 18. Sound of Music

19. Do-er

20. Memory-Maker

 21. Traditions

22. Story times

23. Childrens Books

24. Studio 5

25. Ellen

26. Oprah

27. Matt Townsend

28. Andrea Bocelli

29. Mo Tab

30. Mo Tab Tickets :)

31. Collections

32. Gracious

33. Grateful

34. Detailed

 35. Devoted Daughter

36. SERVICE
37. Thoughtful

38. Proud of her roots

 39. Joy Luck

40. One of Brett's best friends

41. Shopping

42. Lunch Dates

 43. Little Sweethearts

44. Baby Blankets

 45. Laughs easily - what a wonderful quality to have!

46. Patronizes me and laughs @ my jokes - an even better quality!

47. Embroidery/Knitting Bag - where she goes, IT goes!

 (these were taken as part of a 

care package for a missionary)

 48. Testimony

49. Tender heart

50. Open to the Spirit

 51. Parades

52. Gardner Village

 53. Quilts 

54. Seasonal Decor

55. Effort & Hard Work

And so, I am brought once again to the title of this post.

During introductions or referencing you when I speak, is it absolutely required of me to follow "mother" with "in-law"?  I understand using the full title helps clarify my relation to you - I get it, I get it: it's not through blood, only through marriage.  But after a while it certainly doesn't feel that way.  I am as devoted to you as I am my own flesh and blood.  And I feel as much a part of your family as anyone else.  Why can't I just call you "one of my mothers" or my "belated mother" - since you came into my life a little later than my own cherished mom?  

No matter what society requires I call you,

to me your title is worthy of any 

reserved for parents of the highest-esteem.

"How blessed I am,

how fortunate I've been,

that you are his Mother,

and also my Friend."

Happy birthday, Mom!

I love you.