amy, i have a lagun table leg installed in my 16' casita
which is totally different from your tralier. i can tell you that where ever you decide would be a good location will probably mean mounting thru a fiberglass surface. the fiberglass alone is not strong enough to provide a stable mount and you'll need to incorporate additional wood and perhaps some serious "L" brackets.
you can see the plywood support at the bottom of the table leg. on the backside there's another similar (but larger) plywood support so you'll have something to screw into and L brackets tying it into the floor.