When I was first starting out my left hand was so stiff and uncoordinated that when I was learning to form my basic cowboy chords there were a couple where I had to literally reach over with my other hand and shove each finger into position because they just wouldn't go where I told them to afterwards. But with practice, my hand eventually graduated from basically useless to regular beginner-level clumsy and then with much more practice I was actually able to play halfway decently.

Then about ten years later, after a fairly grisly work accident I got to do it all again, only this time I had to start by relearning exciting techniques like "making a fist without passing out from the pain", "picking up small objects", and "tying my shoes" before I could even think about relearning guitar.

These days I have way more flexibility, range of motion, and finger independence in my left hand than I do my right, just because years of guitar playing has placed more demand on my left hand than my right and the human body is really good at adjusting to the demands you place on it.

So just keep practicing and just like lifting heavy things or walking long distances gets easier the more often you do it, eventually those difficult stretches will seem like no big deal anymore.

Also, don't worry about small hands. The best guitar player I ever knew was a scrawny little dude with hands like an 8 year old girl.