It is not unusual to have the mother (in this case the mother-in-law) play the schemer. Remember Rebekah who “commanded” her son and told him to obey her as they plotted to deceive old Isaac who could barely see and hear? So in this case in Ruth, Naomi tells her daughter-in-law how to seduce Boaz which would provide Ruth with some “security”. They come up with a plan that Ruth would go to Boaz’ threshing floor, where he is working late into the night. The plan is to once he is asleep because of the hard work and the satisfying food and drink, that she would go and “uncover his feet”. Now, just so people are not scandalized, this tends to be a euphemism, uncovering of feet, for the removing of the clothing and revealing the male, you know, that. You see that phrase “uncover his feet” in a number of other Hebrew writings.
If you notice Boaz does the correct thing which is to refer Ruth to another relative who was more closely related and sends Ruth off with enough grain to eat and sell and make some money off it. Naomi is quite excited about how things are progressing and tells Ruth that she just has to wait for the deal will be finished the next day, one way or another. The Bible is not devoid of people scheming and plotting and coming up with ideas on how to get ahead without other people interfering much.