As advised to you on your other thread, breed, age and size are irrelevant in bonding rabbits. As stated above, what matters is that the rabbits get along. You need to choose a second rabbit based on this or you could end up with two buns who have to be kept seperate or you having to rehome one, and/or vet bills from fighting.
It can be a tricky business there is just no way to tell. Sometimes rabbits will meet, sniff each other and then be instantly in love and best friends for life, other times they become sworn enemies for no apparent reason.
If you go to a local rescue they will usually help you with this process and try a few different rabbits to see which one your existing bunny gets along with. This also comes with the added bonus the bun will already be vaccinated and neutered.
Wanting a particular breed/size/ age is really about your wants and not what is best for your bunny. If you haven't bonded before and want to choose a bunny based on looks or not from a rescue then you need to do lots of research on bonding and ideally have an experienced person lined up who will be able to help you.
Also, princess will ideally need neutering first if she isn't already. This is not just to prevent pregnancy but also will reduce hormones and terrotorial behaviour that may cause fighting and also prevent uterine cancer which she will have an 80% chance of getting if you leave her intact.
I realise you are young and that is comes down to your parents as to whether they will get her neutered but getting another girl isn't a good solution, two unneutered girls are likely to fight and cost money in vet bills.