Hi, Ig G positive implies that she had a past infection of rubella and has developed immunity for rubella, so she need not worry about it. it means that she will not get rubella again. So it will not affect your baby in any way. All other virus negative means she has never had infection with any of them. That means she could get them in pregnancy. To avoid these she should take care. Eat washed and cleaned vegetables and fruits, avoid cat litter, eat properly cooked meat these will prevent from toxoplasmosis. Syphilis and herpes are sexually transmitted and can be avoided by using condoms. I do not see any problem for the mother or the baby. Hope this helps. Regards.