I have no personal experience in these matters, but the Va. Code strongly indicates that in order to transfer guardianship, a petition would have to be filed with the court, and a guardian ad litem would have to be appointed to represent the interests of the person over whom guardianship is sought. See Va. Code secs. 37.1-134.7, 37.1-134.9, 37.1-134.16. A guardian ad litem, though, is not by definition adversarial. A GAL is simply an independent representative, charged with the best interests of his/her client. The GAL has the authority to oppose a transfer of guardianship, but s/he also has the power to decide that the proposed transfer suits the interests of the client, and to indicate to the court his/her consent. Final decision is always up to the judge, of course. Typically, the party filing the petition to change guardianship would be charged with paying the GAL's fee (although presumably alternative arrangements may exist in cases of financial hardship).

Disclaimer: This is not legal advice, and no attorney-client relationship is intended or should be implied by this comment.