Legal Question in Wills and Trusts in Virginia

I am not sure how it is being used, but I would think it simply means the value of the house AS OF the date that she died.

A good appraiser can give you an appraisal not only as of today's date, but also as of a particular date in the past.

So today you could ask a good appraiser to appraise what the house WAS worth on the date of death, such as (for example) 6 months ago.