The mistake some people make is assuming a strong female character is physically strong. That is not what strong means. Leia has always been a strong female character. She was the classic princess in prison, but she grabbed the blaster and found her own way out. Strong means a character that is independent and realistic without being a stereotype. I think that fits Rey very well.
As to what her trials are, well, they are very internal. Yes, Star Wars has always been part action, but let’s remember that a lot of what Luke went through was also very internal. He had to overcome his disbelief in the force. Rey has to overcome her need for her parents or replacements. Luke was never weak. He was quite willing to pull out a blaster before he learned how to use his lightsaber. He learned the lesson of deflecting blaster bolts in just a short time on the Falcon. Learning force powers was so unimportant to his journey, we never even see Anakin train. Qui-gon gives him a tiny lesson and Anakin flys a Starship (after winning the pod race and we know he raced in at least one before that). So he could fly and he took out the droid ship by accident, not skill. Rey is more powerful in the force and she picks up everything she learns after seeing someone else do it. Her skills don’t come out of thin air, but from Kylo mostly. But the struggle of learning the skills has never been part of Star Wars. Luke had no trouble learning the skills, only in believing he could do them. Anakin’s struggle was in letting go of his mother. We never see anyone struggle to learn the force. Never. Their struggles are within themselves. Luke won, Anakin lost, and we have yet to see what will happen with Rey (though we can be sure she will win hers in the end). So while Star Wars in on the surface an action movie, it is much more and always has been. It is a legend/myth for the modern age and when we see how Rey’s journey ends, we will see again a very internal struggle that ends up saving the galaxy while at the same time a larger battle takes place the reinforced her victory.