If going with a zero power finder like the well recommended Telrad, then also consider a DIY peep sight.
A small block of pine 2x2 wood 6" + long, with an eye screw in each end.
One larger toward the sky end, one smaller toward the eye end.
They can be fine tune aligned once on the scope, by bending them little to the right or left, and threading them in or out of the block of wood, as needed.
The small 2x2 of pine is what gets screwed or glued or velcro'ed to the sono-tube near the focuser.
Long thin shank eye screws(or screw eyes), so they can be adjusted by a little determined bending, rather than pounding.
PVC coated or fuzzy velcro or tape on the eye end one will protect peoples glasses, in the dark.
Grab several different sized of eye screws at the local hardware store, to look through to pick the best two.
Two pin sights work also, but are kinda dangerous to eyes, especially for kids in the dark.
Two V blocks work too, but are not as easy to adjust once mounted.
All zero power peep sights, whether eye screws, two pins, or V blocks are basically impervious to...
dew, frost, batteries being left on, most accidental impact and presumably theft. IME