So I'm getting ready to apply to grad schools in physics, and I did 2 different research projects as an undergrad. Thus I have 2 LORs from profs I did research with. However, I was unable to get a 3rd research project, and hence my 3rd LOR will have to come from a prof I just took a class with, so it'll be much weaker than my other two. The reasons I couldn't get that 3rd LOR are below, as they were related to my father's serious illness:
1. Last summer, I got accepted to 2 REUs. But they were far away from where I did my undergrad at. My father had been given approximately 1 year to live following December 2007. So in summer 2009, he had already exceeded his expected days. Thus, I felt that anything could've happened to him, so I was very hesistant to go to an REU far from home. I applied to these REUs at the time, knowing his condition, I guess as a back-up plan. That is, in case he seemed healthy enough for me to leave for a couple months, then I would've felt more comfortable going. I also decided not to do an REU at my school as I wasn't terribly interested in the available projects. I wasn't aware of REUs at nearby universities, as I looked at the schools offering REUs, and didn't see any nearby, but I now I don't think I looked carefully enough. Then, I got REU offers at 1-2 schools, so I was hesitant to accept them.
BUT.. I was also thinking about getting some industrial work experience, so I applied to some industrial internships, eventually getting an offer from a small company. As this was much closer to home than the REUs, and because I wasn't 100% sure I wanted to pursue research as a career, I decided to accept this internship
2. Last spring, I was accepted to the SULI program at Argonne for a project. I really wanted to go, but at that time, my father was doing much worse than before, and my family knew he probably wouldn't live past the duration of the SULI program. Thus, I had no choice but to turn down that offer, and stayed at home for his final days. Again, I applied because at the time, he seemed to be in only slightly worse condition than before. Since he had already survived this long, perhaps he could last longer. But the time I got the offer, he was doing much much worse.
BUT, I decided not to find a prof at a nearby university to do research with, as I instead commuted to school to take engineering classes (and immediately after my 2 classes ended, I would come home to see my family), because at the time, I wanted some exposure to mechanical or materials engineering. None of the ME profs wanted to take me on, and I don't think any of the materials profs did either. I applied for the SULI in the summer, but got rejected
So as a result, I was thinking that perhaps I could mention this (possibly on my SOP), as to why I couldn't get a 3rd research project, and hence get a stronger 3rd LOR. But I don't know if these excuses are valid. For the 1st one, I should've looked for more carefully for REUs closer to home, or just did the REU at my school even if I didn't like the projects. For the 2nd one, I should've just found any prof willing to take me on. Should I mention this or not?