I don't know if it was a random Glitch or not, but has anyone else taken a stroll around Skyrim, only to find Serana taking a random stroll by herself?

I decided to take Darkeetheus as a Follower, gave him a chance to come with me around Skyrim on foot. I killed two Elder Dragons in my travels, one of which was North of Whiterun. I then started walking back to Whiterun from that abandoned fort where bandits have taken over West of Whiterun. Once I got to where the broken watchtower is, I could see a Silhoette of someone. I went closer, noticed they had a hood and a cape, then noticed the slim female figure, aimed my cursor at her, and it was Serana.

Is this normal?

I've run into her wandering before. It was on the road between Falkreath and Riverwood.