Our Renie had this surgery several years ago and has done very well since, no problems at all in that area. I would suspect that the leaking you are seeing now is not related to the surgery Fiona had. I would have her urine checked for a UTI first. If no UTI then I would suspect she has spay incontinence which is not unusual and can generally be treated successfully. Our Bridge girl Maggie suddenly developed spay incontinence at about 8 and was prescribed a low dosage of PPA which took care of the incontinence.
There are certainly more serious causes of urine leakage, but I would start with the simple ones.
Obviously I'm not a vet, but just giving you our experience.
Definitely.