Dimity's Dragons is a future Earth and Space exploration story. 

Global warming is killing earth. Sea levels have risen - and a super warm planet is causing severely destructive storms and erratic weather. A brilliant young woman develops a theorem for faster than light space travel, and mankind begins the slow expansion into space. A planet is found, although barren, it can support life. With a suitable atmosphere, similar gravity and water in the frozen polar caps - a colonisation starts. However, decades later, monsters attack and the colonists struggle desperately to survive.

In another world recently discovered, a young surveyor finds a portal, through which are dragons. She manages to befriend these dragons, who are sentient, and can mind speak. They guard ships left long before by another race of beings.
Because of her mind link to these dragons, she can operate these ancient, but extremely powerful craft. She goes to war with the monsters and defeats them. However, the knowledge bank of the craft reveals that the monsters live on many worlds.

A mysterious human looking man of Earth folklore, called The Healer - appears throughout. 
An old woman, this one human again goes to war, alone, again believing she will die for her people, against as many as 2 and 1/2 million craft. It is the war to end all space wars.

At the last minute, her oldest friend, the Dragon Queen Lorr, joins the battle, and breathes fire on the monsters, who are also enemies of the Dragons.