Kelli, extranjera just means a foreigner (female) or foreign as in a foreign country. It is a polite term, not slang or possibly insulting as gringa would be. I thought about using La Gringa as a username but decided it was divisive as it can be an insulting term depending on how it is used and also depending on the generation of the listener. It's one of those words that is becoming less charged because it is being used without insult by the young but that still is very insulting to the older generation.
Funny how I sometimes still think of myself as part of a younger generation. I am not. Today I was out on the roof with the architect and job boss and I was touched by how careful they were to make sure I got out there safely. It's full of stuff and the beams are not cemented in yet so they are not really stable. I watched the architect lightly leap from beam to beam as they wobbled and I was not at all sure how I was going to get out there. He came and held on to my hand and walked me on the more solid parts until we were in the clear. When it was time to leave he insisted on getting up first and then walking me back again. I felt like the old lady I am and to be honest I was very grateful for the assistance.