What Are The Uses And Side Effects Of Rubella Vaccine?

Hi, we recently moved to France and my partner is pregnant in week 8 and we recently did a blood test that highlighted the IgG level to be low (around 3). The lab that did the blood test highlighted it as abnormal level. However, our GP (in France) suggested that there is no risk and asked us to do a monthly test for toxoplasmosis. I did a little research online and realise that the low IgG level is related to Rubella and found out that my partner has never been given the rubella vaccine. I also found out that there could be risk to childs eye-sight or hearing, which obviously would not be detected by ultrasound check scheduled in week 12. What are the risks and what would you suggest we do to ensure minimum risk to the child? should we think of abortion?