There are some options, depending. More can always be said on the matter, so if anyone else would like to contribute, please don't let this compilation of previous posts stop you! We always welcome more answers from anyone who can. While we wait for new stuff, OP, here's a few posts on widowhood that may be of interest:

• u/Herissony_DSCH5 examines the legal rights of a widow in England;
• and u/sunagainstgold has an answer on a post very similar to yours;
• and bonus, u/BRIStoneman addresses widows in Anglo-Saxon England, though it's bonus mainly because it's before the Crusades.

In addition to the links DanKensington posted, I have a couple of previous answers that might be helpful:

I am a soldier who dies while on Crusade. How does my family find out?

Did European villages have any major issues after a crusade was set out for by their lords and soldiers? IE Protection, trade, socializing?