Danger on the Ranch by Dana Mentink

Her child's life is on the line...

After putting his serial killer brother in prison, former US marshal Mitch Whitehorse chooses a solitary country life - until his brother escapes. Now Mitch's former sister-in-law, Jane Reyes, needs protection...for herself and the toddler she's kept a secret. Mitch still isn't sure of Jane's innocence in his brother's crimes, but to keep his nephew out of a killer's grasp, trusting her is his only option.