I don’t know how much time she has to kill, but in that situation I’d be tempted to shoot for Gold for almost 2 years: 1) let Silver expire, as she’d still have the Silver benefits until the end of August; 2) use a TP-optimised OTP-PHX fare in mid-July to kick straight up to >1000 TP; 3) tag on the domestic US sectors to the end of that to get her where she actually wants to go (if possible, racking up some more business class TPs en route) - ending up at perhaps 1200 TP before the work Y travel kicks in. If she’s really keen she could even fit in a short TP run in the US while she’s there...

But even if she doesn’t, that just leaves a few nice weekend trips for the two of you, or a short European TP run,and she could have Gold from sometime in autumn this year until summer 2020...