Advice needed on stock and herd number ownership

So a quick backstory, my parents farm was 55 acres. They transferred 35 acres to me about 4 years ago and kept 20. My dad doesn't farm anymore but my mam still keeps about 40 cattle. They still use some of the 35 acres as at the time I said they could farm as much as they wanted, I just wanted to do the transfer before turning 35 years old. Mam has now decided to cut back numbers again and give me the use of the full 35 acres. For the past few years I've been growing barley and cutting some silage for sale. I have a good off farm job which I intend to keep, but my wife wishes to leave her part time job after her maternity leave is up.

So where we are running into difficulty is with my wife and I wanting to keep stock ourselves. Currently the farm yard is tied to my parents herd number, so we can't use the facilities if we were to get a herd number. The yard and sheds could do with some improvements but not in terrible shape. I'd prefer to spent money on this yard as opposed to building another for a few more years and being left with 2 yards on a small enough farm. My mam doesn't want to form a partnership so that's out. We'd rather not wait x amount of years for my mam to retire, but don't want to stop her farming either. 1 option I considered proposing was for me to take over the herd number and let mam keep how ever many cattle she wants but in my name. I could then pay her a wage out of the farm for whatever profit her cattle leave. Does this sound like a workable solution or am I missing something. Sorry for the long winded post and any advice or help is greatly appreciated