In general, becoming indignant is a good strategy for dealing with people that are manipulating you deliberately. Not many people are willing to follow that strategy with their immediate family, however.
Personally boundaries can be discovered, expressed and executed without indignation. Learning how not to get caught up in patterns that personally detrimental while minimising unhealthy forms of conflict is an invaluable skill.
Providing technical support is, after all, an optional service. It isn't an obligation that you have to the world simply because you have the capability. People may be able to influence you to provide that support either by providing incentive or by making the experience of giving the favour rewarding in itself. Helping out of a frustrating sense of obligation is a less healthy and to be avoided if possible.
The Trouble with Bright Girls (article @ the Huffington Post)
Excerpt:
The topic of this article seems to relate to several common Less Wrong issues: the nature of human intelligence, and the gender imbalance among LW readers.
I'm not sure how much credence I give to the proposed explanation of the difference in mindsets. It may well have to do with socialization and feedback, but the specific description of feedback that is presented seems a bit too much of a "just-so story" to me. The difference itself is fascinating, though, and I hope more is done to further our understanding of it.