Is it permissible for a woman to flee to a neighboring country for fear of legal prosecution, after her husband betrayed her and exploited her money, which exposed her to imprisonment, and is it permissible to assist her with money or otherwise to achieve that?

The husband erred by betraying trust and unlawfully consuming wealth, which is a severe harm for which the wife is entitled to divorce. Divorce would be decreed by a Shariah judge if the harm is proven. The oppressed is entitled to flee if they find no means of salvation. Therefore, the wife's escape is considered from several perspectives: the possibility of proving harm to obtain a divorce, the possibility of escaping legal repercussions, the availability of a mahram (unmarriageable kin), and the extent of fearing fitna (strife/temptation) in the country she flees to. If she can combine escaping harm with not committing a forbidden act, that is imperative. Otherwise, she must commit the lesser of two harms. Assisting the wife in escaping is permissible or impermissible depending on the permissibility of the escape itself.