I had a girlfriend for 2 1/2 years and she doesnt come onn to me at all???..hellppp?

she has 4 kids and is just not into sex..she is also 7 years older then me and works alot..shes either to tired or she just doesnt feel like it!..i love her with all my heart and dont want anybody else..has anyone experienced this or is like her??...she says she just doesnt feel it at all but doesnt want anyone else and sshe loves me..is this normal??..will she ever snap out of it?