Hello Bumble.
Welcome to Purrs, although sorry it's under such stressful circumstances, for all concerned.
From what you outline, you have one very stressed cat.
What she's displaying signs of is trying to protect herself from scary stuff - it sounds like she feels things are very out of control, and way out of her comfort zone.
For some cats, that would mean they would hide. For others, they'll attack in an attempt to defend their space, but in either case, it shows a very unhappy and distressed individual.
Is she an Indoors only cat, or does she have access to both indoors and outdoors? How long has she been displaying this kind of behaviour? When you mentioned that it's gone from being just you and her, to an expanded family, that seems to flag up an important change in her life, which she's found difficult to accommodate.
My guess is that the situation isn't helped because the place she's tried to adapt as her chosen space, is a through route, and so can't be kept separate from the rest of the household.
The best way I can describe it is to imagine that you and your cat are sharing a nice peaceful home. Then one day, two complete strangers show up. They're okay people, and well intentioned, but you don't know that. All you know is that you didn't ask them round, or invite them to stay.
They're in your spaces, filling up your world with their personas, whether you want them to or not.
They're bigger than you, and noisier than when it was just you and your Human.
You try to find yourself a place in the house which still feels like yours, but you can't - they're everywhere. Their scent, their belongings - their presence - is everywhere. Remember too, that as a cat, your senses are hundreds of times more heightened than they would be as a human, so this is inescapable. Like being in a thunderstorm and your hair's standing on end because of the static. It's "in the air."
If you're a laid back and chilled individual - no problem. You embrace the change and go with the flow. If you're nervous, and value most what you had before, you're going to become worried, anxious and irritable. You can't escape anywhere - they're always passing through your space. Why can't they just leave you be?
Given that you're proposing further major changes, including a baby and a move of home, I think you're right to be concerned.
Unless your home is going to be much bigger, with a designated space where your cat can hang out undisturbed, things will just get worse for her because nothing will smell familiar, and her sense of being unable to protect herself from what comes next is going to intensify, especially if a new baby is added to the mix.
Whilst there are things that you can do now to try and ease the situation, for example using plug-in's such as Pet Remedy and Feliway in each room, sprinkling Zylkene on her food, and reducing her world down to a more manageable space that others are told to avoid, my own feelings are that this really may be a case of finding a more suitable, quieter home for her. Ultimately, that may be what she responds to best.
I think we all understand how devastating this would be for you to contemplate re-homing a much loved friend.
But for her world to change so much as you anticipate, if she's not handling the current presence of your partner and his son, and normal family life, it doesn't bode well for anyone's happiness and wellbeing.
If there is somewhere in the house where she currently likes to be, could you put her a shelter of some sort there, with food, water and a litter tray nearby.
Somewhere preferably you can ask others to keep away from. What she needs is to shrink her world down to an area she can feel safe in, and where she can regain some confidence. From what you describe, I doubt this will be feasible under your current living conditions.
If you do decide to give her up, I would make sure that it is to somewhere like Cats Protection, and outlining her current personality traits.
From the sounds of things, it would be vital for her that the person taking her knows of her current position, and who is experienced with a more sensitive cat.
Cats are wonderful and amazing creatures, but what most don't like is radical change. Some cats can roll with the punches and adapt, others can't.
If your girl is an indoor only cat, then any changes which happen to her are going to be even more major than you might imagine on the face of things. We used to have a cat that I loved the very bones of, but if you changed so much as a cushion cover, he'd get worried. Now we have three cats, and two of those get worried if anything new appears in their environment. It can happen to any of us.
What we have to do, as cat slaves, is put the welfare of the cat first. They are helpless to change their world unless they vote with their feet and leave. That makes life very precarious for them.
You're entitled to have a happy and fulfilled life, with a partner and children, but those are choices that you can shape and actively participate in making.
Your lovely cat companion can't, so if it isn't working out for her, finding her a home more suited to her needs is a kindness, and a loving gesture.
Not an easy decision to make, so please don't take my words to sound pitiless, and rest assured I make no judgments.
What is her name, by the way, and what does she look like? Have you been together always?
