Hi & Welcome.
I appreciate your concern for your beloved mother who is taking "blood thinner" Warfarin for her prosthetic heart valve to prevent 
thromboembolism.
Nonsteroidal anti-inflammatory drugs like Ibuprofen reduce the pain or inflammatory swelling by decreasing the prostaglandin synthesis. The lack of 
prostaglandins prevent the aggregation of platelets responsible for the clot formation and thus bleeding can be an important side effect of such drugs.
So, if taken together with Warfarin Ibuprofen may increase the risk of bruising, bleeding, vomiting of blood, blood in the urine or stools, headache, dizziness or weakness.
It is better to avoid giving her Ibuprofen as long as she takes Warfarin.
For her body aches and pains which are not relieved by 
Paracetamol alone, an 
opioid analgesic like Tramadol or Codeine may be added along with Paracetamol after consulting her treating doctor.
Remember, in order to keep her Warfarin at an optimal dose the periodic lab tests such as international normalized ration (INR) and 
prothrombin time should be maintained in their normal ranges.
Hope these answer your query.