I feel your despair Julie
You find the same situation with pedigree sows - they've had hundreds and hundreds of pounds invested in them but they're only ever worth what someone's prepared to pay unfortunately
I had some old pedigree sows a couple of years ago, Large Blacks, very valuable in terms of bloodline and breeding but coming to the end of their breeding life. They weren't worth much in cash terms and I worried about where they might potentially end up if I sold them, having had a very relaxed and pampered life here. In the end I took them to slaughter myself. Not because I'm a heartless witch, but because it was the only way I could guarantee they'd have a stress free death and not be mistreated.
It sounds like you might be quite stressed (coming from someone who knows the signs!) and this isn't the time to make big decisions.
If you want to sell weaners in March / April time you'll need to get her to the boar in Sep/Oct for Jan/Feb farrowing but if you don't have anywhere for her to farrow (you could make a pen in an existing shed with just a couple of field gates
) you've answered your own question.
If you do decide to sell her you'll have to accept that she's not worth what you've spent on her and you'll not be able to control where she ends up or how she's treated.
I know it's a hard choice, but you might be best to send her off, get a pork market established and spend time getting accommodation sorted for your next pigs. Ideally I'd suggest buying a pedigree in-pig sow or gilt (a young sow is generally a better choice for a novice breeder, as they've done it before) and starting over when you're under less pressure.
Karen x