Anyone have photos they can share on how they set up rooms where both kids (under 2) stay?

I have an almost two year old and almost 2 month old and when this little baby is about 3.5-4 months I plan to move her from the bassinet into her sisters room. She will be in her own crib of course.

Is it safe to have them both in there? How should I set it up? My two year old is still in the crib and I haven’t turned it into a bed just yet... it makes me nervous since all the bedrooms are on the second floor. I don’t want her roaming around in the morning unsupervised.