To be honest even if it is a bottle that has the ball that moves, I personally still wouldn't use it, as they can still struggle to drink from it, and its better to be safe with a bowl for water than the bottle where you could run the risk of dehydration.
Also your cage, its not bad considering you got it quickly but those bars at the platform ideally need to be covered up to stop your little one climbing them and getting hurt. Especially as at the moment you have no wheel, and climbing is another way that they let out energy when there is no wheel available but they will climb up and then just fall down, also if they try putting their head through the bar it can get stuck which is a reason why its not very safe. So you'll just want to cover the bars up high around the top of the platform bit.
Those ears look a little tattered too, get some coconut oil and just rub it on the ears, this works great for helping them.
When I touch Holly's I start slowly and gently at the top and then work my to touch the rest, have a go and see is you touch the ears then try the coconut every other day for the ear.
She seems to be very relaxed with you !! Which is really great.
If you want to be 100% sure it is a she, boys have what looks like a belly button (for their man parts) and girls don't - this is the easiest way to check.
As for the biting, are you washing your hands with unscented soap before handling ?? If your hand smells nice then your very likely to get bitten.
Another reason could be that she's scared or she's had enough of being handled. Though to not reward the biting you don't want to put her back straightaway. Theres a sticki on biting in the in the personality and behaviour section.