Charlotte stopped sleeping with us (as in, that was her bed, all night etc) at around 6 months as DH was having probs sleeping with her in the bed.

However, would still come in after her 2am feed and sleep the remainder with us.
She continued to co-sleep partially with us until she was about 18 months old. This was due to circumstance more than desire, but none the less, she now comes in after 4am or whenever she wakes up, has a cuddle and now not BF, we get up and have breakie.

However, I would not continue to cosleep until 7 or even 5 for that matter, and perhaps this is what the woman is referring to. We had to "train" Charlotte to sleep in her bed, her room, and we are now going through a resurgence of protest about this lol which requires more "training" - or more politely, return to older methods, like sitting with her and dealing with her waking through the night.

Not keen on the training phrase as it does seem to suggest CC or CIO techniques or that sleep training should be done from a young age. Realistically for me, if it becomes detrimental (ie family is sleeping in the lounge) it is no longer healthy and is affecting the family, and gone too far. But getting (some) kids to be happy sleeping on their own, in their own beds and effectively doing it, does require repetition and education of the child.