Yes to parental controls. Yes to having a roku app. I have never used either. Usually I watch straight from the server, or streaming to my android devices via the android app. They have several installation methods depending on which Linux distro you are using. There is also an unofficial flatpak version of the jellyfin server if you just want it up and running no hassle in under 10 minutes too.
Discussion
Yeah, I would almost always be using it via my android tablet, but for family movie nights, we use the Roku hooked up to the TV in the living room, and all pile onto the couch together. I'll check out the Roku app and see how it goes.
Jellyfin has become the most indispensable app in my lineup.
Now that I think of it. Jellyfin is my favorite open source server software now.
Easy to use. Feature rich. Extendable with plugins. Works absolutely amazing. Their community is very helpful. I have absolutely nothing negative to say about it.