What mattress would you recommend for a 50 KG side sleeper with painful hips and shoulders?

Hi Ginny
 
Thanks for your question, 
 
 
At the body weights you have provided, you both require a medium spring tension. This is just to support your body weights. You can now focus on how ideally you want the mattress to feel in the comfort layers, as this is where your desired comfort level will be found. 
 

 
With you experiencing shoulder and hip pains, this suggests that the upholstery layer (comfort layer) on your current mattress is too firm and is not allowing these parts of your body to sink into the upper layers. 
 
I would advise to have a look at a true medium in the comfort layers or potentially even a soft depending on your own preference (whether you would like to sink completely into the comfort layer or not). 
 
The Origins Pocket 1500 or the Artisan Naturals would be my recommendations for a true medium in the comfort layer paired with a medium support (based on your body weights). Both of these mattresses will allow you to sink into the comfort layer slightly whilst still feeling very much like you are on top of the mattress. 
 

 
The Origins Comfort 1000 or the Artisan Luxury would be my recommendations for a soft in the comfort layer paired with a medium support level (based on your body weights). Both of these mattresses will allow you benefit from a total sink feeling in the comfort layers of the mattress. 

 
I hope this helps, if you have any further questions please don't hesitate to contact the office on 0161 437 4419