This romantic, sci-fi action fantasy is set in a medieval world where war is common and survival is a daily struggle. The young heroine, Betha must persevere to overcome beasts, barbarians, ice Vikings, mythical creatures, elves and savages throughout the kingdom who all want her head.

Agreed with all the above.

I'll add that in most cases when you find yourself using many adjectives or genre descriptions in a logline, you know something is wrong.

I think you need to tell us 'why' all these creatures want her head. What is so special about her, or what is so special about her mission/goal that everyone wants her dead?

What are they trying to stop?

Take this as an example: "When she discovers she's the descendant of the last dragon, a headstrong village girl must..." then tell us what her goal is and what she must do to achieve it.