It depends on the site - some are more stringent with security than others. It is possible to get one day "unescorted" passes usually but long-term dependants passes are another matter. Yes, they're usually given to wives, not partners but you can try to get them to make an exception. If they won't and it's costing you money in fees or lost income then you could look for another nursery if that's possible.
There are some bases where it is difficult to get passes - depends on the nature of the regiment/corps based there.
I met my DP three years ago. His XW had started divorce proceedings while he was in Afghanistan and when we met he hoped his divorce would be final within months. Unfortunately it has been a long, slow process. She has refused meetings with solicitors, then accuses him of procrastinating, then doesn't attend meetings, refuses to fill in financial disclosure forms. They have two DC, who my DP has not wanted to upset by going to court, although his solicitor has advised that should be the next step as his XW could be like this for an eternity. One DC is about to do her A Levels so he does not want to go to court until they are completed. I have supported this, thinking these children have suffered enough and don't need to be hurt further.
In the meantime, we have had a DC of our own who is two. I am also pregnant again. Our two year old goes to nursery 'behind the wire' and I have been repeatedly turned down for a dependant's pass to do the collecting or dropping off as the army does not recognise people who are not married. This came as a shock to me. I have never known any one from the military before, it wasn't mentioned when we visited the nursery and my DP thought it would just be a matter of filling in a form. I work full time and apart from not being able to get in and out, the nursery is perfect for our DC who is really happy there.
We have had several instances when my DP has been asked to work away at short notice, and on one occasion he booked me in as a visitor and asked one of his colleagues to escort me. The colleague got busy at work and I ended up stuck outside for an hour and a half, trying to get it sorted, to no avail. The nursery called a member of staff who wasn't on duty in, to make sure they had enough adults for the children who get collected in a two hour window, so they had a spare member of staff to let my DC out. I found it incredibly stressful, not least because I was trying to have a calm conversation with someone who was armed and explain what had happened, and because if we were married, it would all be straightforward.
There have been many other instances where he hasn't been able to do the picking up, and it is always a stressful experience where I either take a half day off work or the whole day. I am self employed and end up losing income, as well as the lost nursery fee that day. My DP is about to go on exercise and he has asked again for a pass for me for that time, only to be told that a discussion is taking place at a high level about whether I count as a family member. His colleague has an unescorted pass for his mother-in-law as she wanted to pop over and have a coffee when she visited over half term recently, which seems very arbitrary.
I am welcomed into the mess, which is on the same site, expected to put on dinners and entertain visitors and colleagues, which I am happy to do, am named as his next of kin and generally fulfil most 'wifely' duties including supporting families who are finding things difficult. In the face of that, it upsets me that I'm being treated like this.
Can anyone help? I can't be the only person in this situation, surely?