Thank you for your question. I look forward to working with you to provide you the information you are seeking for educational purposes only.
An employer cannot force an employee
to return from FMLA protected leave before their 12 weeks of protection are up. If your wife did return she could possibly file a complaint of harassment
under FMLA, but she has to prove they threatened, harassed or intimidated her to return. Also, if she can prove the reason she was terminated was for using the FMLA, then that would be a separate claim for retaliation. However, because this happened back in August and she did agree to return to work and never filed a complaint at that time she is going to need to produce evidence to the US Department of Labor
regarding the employer harassing her to return contrary to FMLA. Other than the harassment or retaliation though, it is not going to be any violation for an employer to simply ask an employee to return without threats or intimidation and the employee agreeing to do so.
So your wife needs to file a complaint for FMLA harassment and retaliation with the US Department of Labor and also the EEOC and they have to investigate.
As far as the insurance issue, the insurance is the employee's duty to check with the employer regarding adding the new child to the coverage and receiving the information from the employer upon the employee's request.