Hey!
Just been scouting over your previous posts - so you mention a few things: she's been quite grumpy, a juvenile and suspected to be a Northern. So let's start with the behaviour of being grumpy. When they are shedding, they are known to be much more irritable/grumpy in general (as I think it's quite itchy/irritating for them during shed). It shouldn't last too many days, our little one changed for around 4 days for a rough reference. You mention she scares you - is she hissing and biting? or charging from one side of the tank to lunge at you? If she's a juvenile, the hissing (and often times fake biting, where they don't bite hard, it's just because they are scared and try to get you away) is quite common when very young (or wild caught). They do it because they are scared too!
So in regards to being scared there are a few things you can do. Firstly, if you've only had her a few days - give her time to settle in. Don't try to handle for 1-2 weeks. Move smoothly, no fast unexpected movements that could be seen as a threat. As weird as it may be gently talk to her as your doing things in the tank, such as adding food. Get her used to you being around and just doing things. Don't try to pet her at this point. I'll quote from another of your posts
"today she started climbing on her soaking bowl and scratching at the walls, does she hate me" - she'll still be unsure what's going on, climbing/scratching walls can be a way for them to find places to escape to. Does she have multiple hides to feel secure in?
If she begins to settle in during the next week or two, you can start to just put your hand in the tank. Initially, not too close. Just hold it in there for some time (you can wear gloves if that makes you feel better, gardening gloves are quite thick but still allows full movement). Some skinks will become used to a hand being present, some may become curious and actively come out. The main thing is to be patient and let her decide at this point. Over time, you can place your hand slightly closer.
Method three (for once the settle-in period is done of 1-2 weeks) - is to begin very short handling. Yes she'll be hissing and could still try to bite when you start this. It's something that comes with having a juvenile (in general, some will be easier!). Go back to the glove method, if she's only a few months old she won't be able to do damage through the gloves. You can try convince her out of a hide using something soft (such as a rubber spatula) and make sure you don't pick her up from above (as instinct will tell them it's a threat). You can dig your hands under the soil and lift her up if she's on the surface. If you manage to get her up, just hold her for a few minutes (still in the tank, I wouldn't recommend taking her out fully until you understand her more). Repeat this until you feel comfortable enough to progress further
For the next parts of your questions; are you able to get a picture of her and enclosure? As then we'll be able to help with identification to see if she is a Northern and give an idea if the setup looks suitable
