Question

merging has caused problems how could be deleted,

Answer 1

Hi Ali, if you hit the edit button, then scroll down you can decide what needs to be kept and delete what is wrong.
Don’t forget to press save changes when finished.
If you need further advice please provide more information, thanks

Answer 2

Please review the other G2G https://www.wikitree.com/g2g/1096256/there-are-two-extra-children-in-samii-3-but-can-not-be-removed

It looks like you have merged some people together that were not the same people, so you may need to recreate some profiles that were merged incorrectly before you can get the children straightened out.