I've a bitch that is 6 years and she lifts her leg when she pee's. She doesn't lift as high as a male but she lifts her leg a little above ground when she pee's... I don't think it's that unusual. I've seen it before.
I have a girl that is 6 years old....she squats to pee...... but lifts her leg to mark on things......she is now spayed but started "lifting" right after her first heat.