her old cage is fine for a smaller bird, i was worried it was a lot smaller! thats not bad at all!
male lutinos are harder to find than females because lutino is a sex linked mutation, so it is much easier to get females...
and in order to get a male lutino, both parents must have the gene. the mother cant be split so she must be a lutino. but a male could be split or visual, HOWEVER it is very bad breeding to breed two visual lutinos... because it makes bald spots, weaker babies, and can cause more dead in shell eggs. so best pair would be a visual lutino female and a split lutino male, but then you cant tell if a bird is split lutino just by looking at it. you have to breed the bird to know if it is split lutino... not an easy thing, but if you know the lineage of the birds you may have a better chance at guessing if your bird is lutino split.
for example. say the bird you plan to breed is a male grey. look at his parents. if his mom was a lutino, he gets the split. if his mom was not a lutino but his sisters were, he may also have the split... its complicated but thats why there are more female lutinos, pearls, and cinnamons out there. because theyre all sex linked. its easier to get more females of these mutations, so it may be hard to find a guaranteed lutino male if you get a baby. to be honest, i would get a lutino female if you want to avoid breeding. because not only would it be stressful on you, but breeding pearl with lutino is also another poor genetic choice because pearls also suffer from thinning of feathers behind the crest to full out bald spots and this would only cause more bald spots in the babies... and cinnamon is even more complicated in the mix. so a cinnamon pearlxlutino is not the best pair. but its fine if you prevent breeding. which in tiels it is very easy to prevent breeding for the most part. most tiels respond well to the long nights treatment
and belle is a girl no need for testing. if she grew in pearl tail feathers, shes definately a girl, no way around it