Not necessarily. Identify actual proceeds and relevant transaction costs or restrictions without assuming the quote is a settled bank balance. Two numbers are needed and only one of them is on a screen. The first is what the holdings would actually realize after a sale: fees, spreads, any withdrawal limit, and tax payable on the disposition. The second is the total obligation in United States dollars for every intended applicant, taken from the current official terms. Compare those two before deciding anything else. Nothing here is tax advice, and the disposition should be reviewed by someone qualified to give it.
Use real amounts rather than a price prediction
The government amounts remain the published U.S.-dollar processing charges and gifts. This page gives no exchange rate, sale recommendation or tax calculation; review the actual funding plan separately from the immigration decision. Currency is a control question as much as a cost.
Funds converted early sit in dollars and are exposed to whatever happens next; funds converted late are exposed to the rate on a date nobody can choose. Neither is a recommendation, and this page offers no forecast. What the family can decide is the tolerance: how much of a shortfall would be manageable, and what the fallback is if the realized amount falls under the obligation.
Write that fallback down before the first sale instruction is given, because the moment to think about it clearly is not the moment a market is moving.