John Bowlby was the psychologist who originally argued that 0-5s need a mother and that separation from their mother could cause distress and later on, psychopathy.
His views became very influential and were used by the government just after the war, to get women back into the home so returning men could take their jobs.
Many subsequent studies have discredited Bowlby's theories. It is now recognised that babies are capable of attaching to multiple carers and indeed thrive from these attachments.
So OP your grandchild will love having a weekend with you. Her parents are putting her needs first in allowing her to form multiple attachments.
What to do with immigrants? - ask Shakespeare
Reducing contact because my heart just isn't in it.
"Old fashioned" expressions that young people have never heard.



and she will love staying with you!