Keep in mind Obligation is not just like you owe someone something, but it's something that can come into play and complicate life. This has to be something serious enough that mere mention of it is enough to cause your character stress. Owing a former colleague some money is ok, but what about that situation is causing her stress and anxiety? Great examples of Obligation are of course the debt Han had t Jabba for a botched job, the Chewbacca family obligation highlighted in Solo, the ties of brotherhood some of the Clones had to each other in Clone Wars and so forth. You might consider an obligation related to her honor code. Perhaps she violated her code some how to obtain those items and that still haunts her and she is making amends for that breech. Could also be an enemy or something related to the destruction of her previous unit.