Is it permissible for the brother of a deceased husband to marry his brother's widow, despite the objection of some of his siblings who claim that his financial income does not equate to her current pension, and that the marriage will affect the stability of her financial life and possibly distance her children from their family?

It is permissible for your brother to marry your brother's widow if she agrees, and if her guardian marries her, provided he is suitable. Marriage provides her with stability and the care of a pious husband, in addition to her retaining custody of her children. Travel to America is generally forbidden due to its danger to religion and morals, unless there is a legitimate need recognized by Sharia law, and provided that there is security from temptation. Advise him to fear Allah and not to expose himself, his wife, and his brother's children to temptation by residing in lands of disbelief.