Cracks in the Shower

[flycaster]

We are full timers in a 06 36ft RS3. We noticed the other day that there are a sreies of fine cracks (black lines) in the corner above the soap dish of our shower. They just seem to have appeared as neither of us remembers any damage before. They occured while we are in Arizona this winter. We have not noticed any extreams in temperature or movement. I've seen these sort of cracks before in old fiberglass. I don't think that they are leaking but I am concerned about them when we start to travel this spring. Has anyone experienced this and should we be concerned? Is this something DRV has addressed before? Any help would be welcomed.