Hiya
Certainly with my pump, the tubing is double skinned and you can easily mark the tubing itself, if you've got one you threw in the bin recently, dig a thumbmail in it - sometimes under clothing they go in a fold as opposed to a loop (esp under eg waistbands etc, and I imagine, elasticated clothes might do it) At first glance, these can look a bit like air bubbles.
If there is any doubt in your mind - new cannula, new tubing and prime, every time. Better to be safe than sorry.
Unfortunately you will have no idea how much insulin has been missed (that applies to adults equally) so it's literally a matter of test, test, test and be a bit 'careful' with your correction at first (ie knock a bit off) until you are sure what's definitely happening to BG.
In what way did it come adrift? - is it all the sticky or just the bit in the middle where the cannula goes in? Could Molly have had something on her skin? - baby lotion, powder, perspiration, dampness from her bath?