The blog said she went to Jordan overland, which means she has entered both.
You're right though that it's extremely difficult for most Gazans to do so, and many will live and die without ever leaving that cramped little strip of land.
Don't forget the fact that Israel blocks imports and exports, meaning the country has extreme difficulties getting e.g. construction materials, nevermind getting an industry going. Unemployment is everywhere, misery, disaffected youth (as is understandable)... is it any surprise resentment and hatred proliferate?
You're right though that it's extremely difficult for most Gazans to do so, and many will live and die without ever leaving that cramped little strip of land.