adopting older kids w/ biological children in the house - questions

I guess I'm not that sentimental or have an aversion to extra knick-knacks to clean around. I don't display out of date personal portraits, just family events (wedding) and current portraits. Big sis (bio) does have many pix in her room, including one of herself and dd2 in a sisters frame but she has another with all three. We do have an out-of-date family photo waiting for dd3 to be included for an update. She is older and having this done will be a part of the adoption for her that she is looking forward to. The handprint casts and prints of preschool and other preK and K paraphernalia went into the kids' memory boxes around 1st grade, so those aren't out, either. I'm pretty sure at the time that I transitioned these decorative objects out gradually. I'd guess it also depends on the ages of the newcomers. If they are not all that old (under 5), you may be surprised by how new mementos of them slide into the mix--you could even deliberately make some, as a statement of sorts. Regardless of age, you will probably be surprised at how fast mementos of them will overtake the end tables, piano top, stairwell and hall. If you are inclined to have lots of this stuff around, I suspect it will very soon be a mish-mosh of everybody.