congratulations on your new bunny!
that is very exciting news!
her cage sounds great- but if you want to get her a bunny-buddy i would suggest doing it soon - as your place is still new territory to her. the longer she is with you the more territorial she will get. this is especially true with female rabbits. also, i'd suggest getting a male rabbit as a companion. that would be the easiest bonding pair.
however- if she is four or five already she is probably more than fine on her own. i know having two rabbits always sounds like the ideal situation- but thats not always realistic. for example- i got my two rabbits 4 months apart and to this day they will kill eachother if let anywhere near eachother. i too wanted my first rabbit to have a friend- but it turns out she would have been much happier on her own. although- i love my second rabbit so much that i would still do it all over again. they are both so very special to me.
i guess my point is just be ready to keep them seperated forever in case they dont bond, and if you do get another bunny i would try and adopt one the same age since Rencia is 4 or 5, unless.
this is just my thoughts on the subject, i do think my first rabbit would have accepted a male, but i accidentally got a female and so this is why i think they fight. both are spayed too! so i was surprised they didnt bond better...
anyway! i'll stop rambling now! just wanted to tell you a rabbit can be happy on its own as long as you pay lots of attention to her. but if you get another i wish you all the best and hope they bond quickly and become best-buds!
good luck with whatever you decide! rabbits are indeed very special pets/friends/family members.