At first I thought it was strange but now I feel it is because they are so secure that they feel perfectly safe without us 
We are loving parents who do lots with them both and enjoy being together as a family. DD1 is 5 and DD2 is only 3. Until recently I was a SAHM. I just feel really proud of them ...... they had to go to GPs due to childcare issues but now I am happy we have all experienced this as prior to this I thought DD1 might find it difficult because she is much more sensitive than dd2. 