"she was worked her way up to" equals "she has progressed forward to" equals "she has advanced steadily towards" Work upward, progress forward and advance steadily all signify that a person is doing well. They are all analogies or metaphors. Through hard work you can climb up a mountain, or progress forward through a jungle, or advance steadily through a maze. Those examples are more literal, but how do you describe the effort it takes to go from a minor job "up to" a role in the marketing department of a major hotel group? Well, it can often feel like you are climbing a mountain, or going through a jungle, or navigating a maze, so why not use the same language to describe a career? Personally speaking, I'm working my way up to being bilingual in French. I'm not very good right now and my goal is far away, like it was on top of a mountain, but I'll work my way up the mountain step by step and hopefully reach my goal.

“Working your way up to something” is a very useful and common expression. When I started running, I felt dead after running 3 kilometers. I’ve worked my way up to doing a 10k run every weekend. When he first got here, his English was so bad that he could barely say “hello”. He’s worked his way up to being able to carry on a real conversation. He was only hired last year, but he’s a superstar. He’ll work his way up to management in no time.

Hi there, what an awesome phrasal verb you have found! :D Actually I can't think of an easier way to phrase this sentence; the language used is already very concise and clear. If you try to use more simple language, you will end up with a much longer sentence or multiple sentences. However, to help you understand the sentence let me give you the same information in simpler language: She has worked in many roles in the last several years. She has been promoted to each of these roles by working hard. She has probably only been promoted, never demoted (this meaning is suggested by the word 'up'). Her last role was not in the marketing department of this major hotel group. Her current role is respected by the speaker, and was maybe a goal of the lady in the sentence. Does that help you understand? Feel free to ask any questions you still have; maybe I haven't made it very clear!