My daughter will probably need to change her TD status to F1 status to attend college next year. What implications can this have, if any, on our TN to GC process? Right now, we are waiting on PW approval so early stages.
It is allowed to study while on TD status; it does not necessarily require a change of status to F-1. However, if your daughter "ages out" (turns 21) she will no longer be eligible for TD status and will need to switch to F-1 status at that point in order to continue studying.
For you and your spouse, there will be no impact on the TN/TD to GC process if your daughter switches to F-1 status.
For your daughter, to apply for F-1 status and to re-enter the US in F-1 status if she should choose to travel outside the US, there is a risk that she will be found not to have "a residence abroad", which would result in the denial of F-1 status. However, many children of foreign workers in the US have switched to F-1 status successfully, even though their parents lived in the US for many years.
I am sorry that I could not provide a more detailed risk assessment because this situation is not often discussed on the forums that I read.