Every building has a limit to the amount of people that it can hold. This is normally set by a fire marshal, but if you own the building you can set that limit lower if you want. For example, most apartments that have one bedroom have a two person limit. During this time of year, many apartments will see more than two people in an apartment during the day or even for a couple of nights. I don't know a single landlord that would have an issue with this, especially when it comes to people visiting for the holidays. However, how long is too long to be over that set limit?
During the holidays, most people travel to see their friends and family. This can involve going thousands of miles to see someone for a few days before going back home. Sometimes, however, they may stay for an extended period of time. This is common if someone is coming from overseas or if there are multiple events that are spread over a comparatively short amount of time. For example, a friend of mine is flying from Scotland where she now lives to Texas so that she can spend Christmas with her daughter. She will then stay with her for another almost two months until her daughter's child is born. Staying that long in a hotel is not only uncomfortable for most, but also extremely expensive. However, is it okay to have a resident of yours have a guest for that long?
We cannot answer this question for you as we do not have the special circumstances that are keeping your resident's guest there for an extended period of time. We don't even know if you would necessarily know if this was happening depending on how often you go over to check on your residents. However, it is something to think about. Just how long is too long to have someone staying in your rental property when they aren't on the lease? With the new year starting, it may be something you start to consider if you have a resident with a guest who is "only there until they get on their feet". Each situation is different, but sometimes changes do need to be made.