You haven't answered my question about the lap-sitting (and that is fair enough) so without more context, here is my opinion.
While certainly not every daughter would sit on her dad's lap as an adult, I used to do so, briefly, when I would come home, to give him a kiss. Now he is too frail so I sit on the arm of his chair, which is the equivalent.
I do have a bit of an elektra complex probably - I adore my dad and have found his descent into dementia impossibly hard - as I used to want his advice on everything, crave his approval etc.
It's nothing to do with any abandonment issues - he and my mom are still together. It's just my personality I guess?
It hasn't caused me massive disastrous problems in adult life. It HAS made it upsetting to lose him, so yes maybe more separation would have been better in that sense. But I am still largely a functioning adult with a child and a successful career. I have had a few failed relationships, and I guess one could argue that no man lived up to dad in my eyes? But having had therapy which did look at this, I honestly don't think it's the sole or main issue.
I guess what I am saying is, every relationship is different, families are messy, and yes, sometimes a child can idolise one or both parents to a slightly irrational extent for whatever reason (or none). It is what it is. Sometimes siblings have unusually close bonds too, or people slightly cling to their friends - all kinds of things.
As long as it is not actively harming anyone, and they are both happy with it, it's probably best left, even if she does have him on a bit of a pedestal - does it really matter? You aren't her therapist - it's not your job to root it out....
If it starts to interfere with her happiness or her ability to form relationships, say, or she starts causing problems between you and your husband - then I would consider acting on it. Before that point, to be honest if you interfere you may, inadvertently, do more harm than good.
Of course, if she is, say, sitting on his lap for whole evenings while they watch a movie together, or anything that anybody would identify as properly messed up (sorry to use a term like that) then it's different, and you do need to speak to him ASAP.