Thia sounds like Fifth Quarter by Tanya Huff.

It was published in 1995 and the blurb matches your description:

• brother and sister assassins

• brother body is stolen and his spirit is forced to share sister's body

• hunting for brother's body

It has been a long time since I read it, so I don't know if it has the bit regarding the broken wrist. The cover art is a similar style to Mercedes Lackey's works, so that is another match.

This is the second book of the series but the first with these characters.

This sounds like Fifth Quarter by Tanya Huff.

It was published in 1995 and the blurb matches your description:

• brother and sister assassins

• brother body is stolen and his spirit is forced to share sister's body

• hunting for brother's body

It has been a long time since I read it, so I don't know if it has the bit regarding the broken wrist. The cover art is a similar style to Mercedes Lackey's works, so that is another match.

This is the second book of the series but the first with these characters.

Thia sounds like Fifth Quarter by Tanya Huff.

The blurb matches your description:

• brother and sister assassins

• brother body is stolen and his spirit is forced to share sister's body

• hunting for brother's body

It has been a long time since I read it, so I don't know if it has the bit regarding the broken wrist. The cover art is a similar style to Mercedes Lackey's works, so that is another match.

This is the second book of the series but the first with these characters.

Thia sounds like Fifth Quarter by Tanya Huff.

It was published in 1995 and the blurb matches your description:

• brother and sister assassins

• brother body is stolen and his spirit is forced to share sister's body

• hunting for brother's body

It has been a long time since I read it, so I don't know if it has the bit regarding the broken wrist. The cover art is a similar style to Mercedes Lackey's works, so that is another match.

This is the second book of the series but the first with these characters.