I always think it is preferable if an older child sleeps in their own room but many dont and I do not believe that there is any motive other than parents being close to their children ,and giving way to the child asking out of nightime loneliness, ;can I stay in your Bed Mommy' Very often it starts when Dads are away maybe in the Military and families huddle together for closeness and company. Many of our members have said the same as the old threads here will show ...
in my view just give her some time to adjust with ur rules and let her to be have some little independancy in his way and also dnt force her more about the rules she is still 8 year now 18 year and she need some time to accept the fact of life so give her chance and also make friend with her as much u can don't ignore or do any thing which make feel hurt her feeling. and make thing this way that she can understand u and ur feeling about her and also in my way there is np if she want to sleep with her mom on same bed even if she is with u try to do thing same way she can be more close to u and do some things make her happy more more and she insist to be with u all the time so not force u to go back to her mom. good luck buddy
My opinion is that you have a happy time with him when he is with you, games, fun, outside activities, ignore any whining for his Mom thats natural anyway, make him feel good when hes around you, its up to his Mom what she decides to do about the sleeping when she has him, some families do sleep together, it usually stops once the child reaches puberty and wants privacy.So back off have a good time with him, less talk and more fun..good luck