US Citizen married to U.K. Citizen and green card holder moving to U.K.

Is there anyone out there who can point me toward professional counsel who can advise me and my wife, who by moving back home to the U.K. will be effectively "abandoning" her US permanent resident (green card) status and how that affects us on taxes, expatriation (for her), etc.?  I'm a US citizen who has been granted a spousal settlement visa -LTR, and I'd like help in finding out who to ask about these matters so that we do it right. Solicitor/tax advisor, or who? Specific recommendations appreciated. Sorry if it's a bit convoluted.  Thanks.

I can't help with any professional recommendations, but your wife might consider US citizenship as right now if you ever wanted to return to live in the US you'd have to do the Green Card application again.

Thanks for your reply. Unfortunately, we have now arrived in the U.K. so citizenship won't be an option since she won't be resident in the USA now. So I'm guessing it's too late for her to do. Thank you.