You got off easy. You escaped relatively unscathed.
Emotionally, what do you expect? Do you think your time with them has as large an emotional impact on them as it does on you? Even if you are in the top 10% of clients she has encountered - respectful, sober, good hygiene, not repulsive, witty, and charming, etc. - she will be meeting a new you once a week. The days you spend with her are transitory, the poverty of coming from the second poorest country in the hemisphere after Haiti is permanent. Unless you can whisk her away from her situation instantly, she knows what is real and what is your monger fantasy. What, you think you will work out like it did for William Holden in The World of Suzy Wong?
http://www.youtube.com/watch?v=ewDwOHzg_mUWhy you let her friend & offspring tag along and mooch is beyond me, but if you do that sort of thing, then they will let you be the walking ATM for as long you let them.
Understand this about Nicaragua. For two generations, economic mismanagement, 40% unemployment, strong sense of family obligation, and the idea that succeeding financially is based on pure luck and not one's own discipline and effort, has fostered the concept of "el caballo" or "the horse."
Every family, even large extended ones, have a "horse" or two. Finding a job is like winning the lottery. There might be one, or if they are lucky, two breadwinners in the home, and that job or two will support up to 10 people. Imagine one horse pulling a cart with 6, 8, or even 10 passengers. In the States, most of us will feel a sense of shame about being unemployed. In Nicaragua, it is accepted, and the idea that the gainfully employeed will disentangle themselves from these leeches is foreign to them.
You would be amazed at how many Nicas in SJO are supporting a half dozen people back home.
I was in Nicaragua six years ago. I had given a Nica I met in SJO a "scholarship," meaning that I would give her few hundred a month to leave Idem, go back home, move in with an Aunt, and go back and finish her high school diploma. She was glad to leave Idem, she didn't have the psychological strength for that kinda work. (It didn't work out. Studying, even if you have nothing else to do, is tough. She married another gringo and went to the states.)
Her teenage cousin was having a birthday. I bought them both cell phones as a present. Then I got invited to cousin's birthday dinner party at a restaurant. Cousin, aunt, aunt's terminally unemployed boyfriend, a half dozen other relatives, a couple friends of the family. Another cousin, the only other male at the table with a job, and his girlfriend show up.
At the end of the meal waiter brings the bill and the whole table is pointing him to me. I was the "caballo" for that meal. Employed cousin picked up the tab for the drinks, but I was expected to pay for the meals for almost a dozen moochers. I wonder what would have happened if I had only paid for just me, Nica, her cousin? I was amazed that grown men had shown up and expected another man to pay for the meals and drinks of themselves and their wives/girlfriends. I had visions of giving the waiter enough for a third of the tab and walking away. Would the rest of the party be scrubbing dishes for the rest of the evening? Would they chase after me and my Nica as went for a cab?
When I went back for a visit months later, the teenage cousin was on the look out for me so I could buy her a new pair of Converse sneakers. I avoided her that trip and dubbed her "u-buy-me".
When you took the three of them on their little "moocher's holiday" you told her you were a walking ATM machine and a "caballo."