Like @ErrolTheDragon and @goodbyestranger, both of whom post regularly on other HE forums, my DDs are long past the application stage. I didn't use MN when DD1 applied and wish that I had found somewhere to ask the practical questions that DD would not have thought of. I'm sure I speak for all those of us who are here having been through the process; we want to offer a handhold and to be here to help with some of the questions about a process that lots of people don't know much about. Yes, I'm guilty of being extremely proud of my DDs and their achievements, but on this thread, I have confined myself to reporting having had 2 DDs apply, both get interviews, one get an offer having been pooled, and the other rejected. Pooled DD is now in the 2nd year of a PhD. Rejected DD is flying elsewhere, just about to start her Masters year, so it has all worked out well.
With DD1, we didn't attend the open days because she did a women into STEM course the week before in Cambridge and they talked through the process. We had also visited C in the previous summer and wandered around getting a feel for some of the colleges, although not the one she ended up at. She applied to the one where she did the course. I took DD2 to one of the open days. We had a plan to go to as many colleges as possible, apart from DD1's. She wanted to go to a lecture, so whilst she did that, I went to do some recce'ing for a school choir tour there a couple of weeks later. We both felt similarly about the various colleges we visited, but in the end, the choice was entirely hers. I saw my role as being a sounding board/devil's advocate, which is something I have done for a long time.
I'm equally happy either to remain and help if I can, or bow out if what I type is perceived as "sharp-elbowed" or "crowing".