Because for someone who is new and became a stranger to another country, she has thought the worst that could possibly happen. Robbery, kidnapping and she also considered that if she can't find any way of making money, she had no choice but to sleep on the streets. This beyond possible happenings made her sleep less because of overthinking. But one thing's for sure, she never had any regrets of cutting ties with her own parents.
Is she missing them? Yes. Is that feeling enough to make her comeback to Spain and be dictated for every action she does? Strongly a NO for her. That is why it was so ironic for her to think that she will be able to experience the parenting and the love she wanted from a completely unknown person from a different country.