Is it normal to still have swelling on the cheekbones three months after a mini facelift?

It depends on what kind of mini lift you had. A MACS facelift may lend to some more upper cheek swelling than a standard S shaped lift since the dissection goes farther out towards your cheek. I would give it at least 6 months to see your final result.  Also, make sure there is no fluid under the skin flap.  

Yes it is very possible to have swelling in your cheeks 3 months after surgeryThe healing process can be a long one with a lot of ups and downs.  One day may be better than the next.  It is difficult to be patient however it will all work itself out over time. Now if there is  still an issue at a year and a half that is another story.

Swelling in your cheeks three months after a procedure is very normal. The total healing process takes 12-15 months. There will be much refinement in and maturation of your facial contours in that time. No need to worry yet!

 Hi, I have performed many facelifts over the past 30 years and many, minimally invasive type SMAS facelifts.  At 3 months, the healing should be complete however each face is different and only your Facelift Surgeon knows what exactly was done during your facelift.  You should discuss your concerns with your Facelift Surgeon and get specific post op recommendations on how to reduce the swelling over your cheeks.  While more aggressive and invasive type facelifts like a traditional facelift, mid face, deep plane and sub periosoteal facelifts can have prolonged facial swelling and recovery, one of the reasons that my most popular facelift is the minimally invasive, short incision facelift is that it has all the benefits of more invasive facelifts (traditional, mid-face, deep plane, cheek lift and subperiosteal facelifts) but with these added benefits:
very small incisions and no incisions extend or are placed within the hair.
minimal tissue dissection = less bruising and swelling = rapid recovery measured in days instead of weeks or months with the more invasive type facelifts 
can be performed in 90 minutes or less, with or without general anesthesia
no incisions within the hair = no hair loss
excess fat can be removed
excess skin removed
cheeks, chin and jaw line can be augmented with dermal fillers (I prefer Restylane Lyft) or facial implants
most patients fly back home to parts all over the world in as little as 3 days post-op
Hope this helps.