Since your mother dreamt the name didn't you consider the possibility that it wasn't an established name and perhaps had no meaning at all? She simply created it for her daughter.
The closest I can think of off the top of my head is it's similarity to Welland, first recorded as Weolud in the 900's. It was a Celtic, or possibly pre-Celtic rivername and the meaning has been lost.
Other than that, all I can think of is perhaps the English
Ellen served as some sub-conscious inspiration?
Ellen is from the Greek
Helen meaning 'torch' or 'ray of sun'.
Devon