She's Lao, as you say. If she has not registered marriage outside Norway, then she's still single outside Norway. She could get a letter from her government stating she is single, and a freedom to marry document, which would allow her to marry anyone else.
I don't know about Norway, but in Thailand there's an abandonment option, where one party to marriage can claim abandonment after 1? 2? years, after which divorce can be granted, whether the other party signs any divorce papers or not. However to annul marriage in Norway, the paperwork would need to be handed to Norwegian authorities. It's also possible to do that at Norway embassy, but may be complicated by the part that she's Lao, not Thai.