Low libido can be caused by different things both in men and women (ex: depression, hormonal changes, stagnation in the marriage, low self esteem, etc)
If you believe that it is due to hormonal reasons, some women supplement with Maca, Tribulus and Macuna pruriens (they increase the testosterone level)
You could also try to bring some spontaneity (take her to a nice dinner, give her a massage, prepare a bubble bath tub for her, compliment her during the day, get her flowers, write her love notes and stick to her coffee mug in the morning, etc) It may be a case of boredom on her part. It can also be emotional (depression leads to decrease of libido as well as some medications)
When she gives you the excuses of not wanting to cuddle, be touched, ask her what she would like instead. Don't back up until she tells you. You may say something like "you used to like this..."
First try to see if she herself knows what may be causing her behavior.