E.W.
I think what you are feeling is pretty normal. Some of those slide are very tall and at 2 1/2 she is still very small and probably slightly uncoordinated compared to an older child. I don't see anything wrong with spotting her on really tall stuff and as she grows you'll see there's less of a need and you'll be able to relax more about it. I have 3 kids and pregnant with my 4th and I still spot the wee little ones on high stuff, and my older kids I know are fine and they happily climb and play. So the years of spotting did no harm to them, in other words. You're just a careful mama and there's nothing wrong with that and she will know you are always going to be there for her. ;)