On a side note about the Ostrowski family, the following comes from Paul Robert Magosci's book "Ukraine An Illustrated History". This is from a chapter re the years 1569 to 1648.
"Nearly half of all noble landholdings were in the hands of a few powerful magnate families. Polish magnates ... had holdings scattered throughout Ukrainian lands. The largest landowners, however, were noble families of Orthodox Rus' origin, such as the ..., and most especially the ... and Ostroz'kyis. ...The Ostroz'kyi family was even wealthier. Based in the town of Ostroh, the Ostroz'kyi holdings covered most of the Volhynia and western Kiev palatinates. For instance, the leading member of the family and the palatine of Kiev, Prince Kostiantyn Ostroz'kyi, was after the king reputed to be the wealthiest person in the Polish-Lithuanian Commonwealth. By the outset of the seventeenth century Kostiantyn Ostroz'kyi's holdings included 57 towns, 857 villages, and 111 manorial estates. The Ostroz'kyi, ..., and other magnate families also commanded large private armies that were used to protect their property as well as to serve in defense of the commonwealth's southern and eastern frontiers."
Later in another chapter: "A second ... response came from a small group of Orthodox Rus magnates who tried to raise the general level of their religiously based culture. They did this through the establishment of schools and printing presses, the most famous of which was on the estate of Prince Kostiantyn Ostroz'kyi of Ostroh. There, during the 1570s, the prince established a primary school, a printing press, and an institution of higher learning and research (especially for translations) known as the Ostroh Academy."
So, your Ostrowski family could well have come from nobility.As I also have a friend with the Ostrowski name, I am curious if anyone is aware if the lineage of that family described above has been preserved anywhere.