oval crfaft in a field glowing.

My deceased mother claimed she saw this craft in a field on her way home from an association meeting of Green Lake. She was on her way to get papers that my dad had forgoten when she was startled by the glow in the field and stopped to see.  She sat in shock for a moment and left, shaken.  She made a drawing of it for me before she died three years ago. She was credible as a witness, a mother of seven and not known to tell stories that were not truth. She was not a drinker and didnot take drugs.
Date is approximate.  PD