Tensei Youjo wa Owabi Cheat de Isekai Going My Way

From Google Translate:

She was supposed to be a light-hearted otaku woman in her 30s, but when she woke up, she found herself reincarnated in an unfamiliar forest as a little girl! Thinking that this must be a dream, she decided to take a walk in the forest anyway. Suddenly, she encountered a giant monster. "If this is a dream, I'll use my imagination to my advantage!" she thought, trying her hand at magic, and successfully repelled it with an incredibly powerful attack!