hi again @FearofUnknown!
sibling bonds are so special, and i can imagine that feeling a physical distance in that bond would feel overwhelming. i have a younger sister that i'm close with too but i think i was a bit of the opposite to you. i wanted some space from her to be my own person. we both talk pretty much every single day, but we also are okay if we don't see each other for a couple days.
going from seeing someone everyday face-to-face, to not as much, is a big jump and it's okay to feel uneasy. i see you've mentioned texting everyday but still feeling distant, would you mind sharing what you mean by feeling 'distant'? is there anything in particular that you miss?
in moments i miss my sister but know she's unavailable, i reach out to my other friends instead and catch up with them. if they're busy too, i either journal what i wanted to share with my sis or i do activities that bring me comfort (like watching a movie, working on some crafts, going for a walk, etc).