Cat stopped having kittens

Question
I have a 4 year old female ragdoll who has not had kittens for the last 2 years.  She does go into heat but had not given birth to any kittens.

Answer
Hi Marilyn
First off I presume she has had a litter of kittens, so she is probably fertile albeit not 100%.
Now if the stud is proven then there may be problems with the young lady and her fertility.
Can I ask did she have a normal pregnancy in her last litter?
Has she suffered from any urinary infections during the past two years?
Has she had any abdominal operations in the past two years?
To be on the safe side ask your veterinarian to do a full cbt on her to check for any abnormalities, disease etc, before continuing.
If the answers are no and she is all clear then...
Let me suggest the following
1. Give her bottled water from now on, make sure it is fresh everyday, any left over throw away and refresh the bowl.
2. Give her wholesome foods, fresh meat,fresh chicken if you do give that to her and plenty of food containing vitamins and minerals, see the dried food package for contents.
3. When she has mated you would need to obtain Synulox from your veterinarian and administer that to her for the next three weeks. Why this, well it works for queens who have low fertility levels.

Now you will know whether she is pregnant by about day 21 if she 'pinks up'
However if this fails then one other drastic action is a do an outcross as a trial mating to test her virility against other ragdolls. This is extreme I know but you may have encountered something called inbreeding depression in your queen and an outcross will encourage mating vigor which may result in an active pregnancy.
If you require any further help do get back to me

Ray