We are frequently seeing this situation that you experienced with your daughter during the exchange of lower incisor teeth. When permanent teeth germs are not growing right under the deciduous teeth they grow backwards so they can erupt without resorbing the roots of deciduous teeth. Unfortunately, in this situation they should be extracted by a dentist. However we see this situation frequently on lower incisors. Other teeth, especially upper incisors are exchanging by themselves. Thus, don’t worry. Our recommendation is to see a pedodontist in other words a children teeth specialist for extractions of those teeth and to psychologically prepare your children for extractions. As you told, you should live this situation which is very important for your children and which is an indication of growing happily and together.