>>She was about 3 years old, I had her since she was a baby.
What a beautiful wd...what a shame 
I know you said she layed her eggs in the pond...did she perhaps need the warmth of the water to aid her in laying them (it's supposed to relax the muscles, and animals know this instinctively)? Could it have therefore been neurological?
If you decide to ask the vet for an exam to let you know what the cause was, let us know, so we can learn from it.
I know you just built that massive wd rom too.
Again I'm very sorry 
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Yours,
NiCoLE
"Trying to save someone from their own stupidity is like trying to teach a pig how to dance: it wastes your time, and annoys the pig."
- Robert
Heinlein
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