Nope.
So you do normally use the field without a 'shelter' then.
You pay for grass livery, you still had grass livery. I'll put money on there being shelter albeit natural (hedges/trees/hill). As for being 'denied' running water, we are talking about a hose pipe connector (£2 tops).
I guess you can't reason with stupid, so I'm going to give up trying now.
...
Its a grass livery DIY but for this amount we have always had access to the field shelter and water...For years infact!First of all £70/month is amazing - i pay £70/week for my 2 at livery!!!
And as others have already said - sheep are EXCELLENT at restoring grazing! They eat all the rubbish up, and convert it into little ready-made/evenly distributed fertilizer pellets
If your YO was going to have to pay a contractor to do the same work the sheep will, I'd expect your rent to double, and you'd still have to rest the fields for the same length of time, possibly more because the ground would have to be ok to drive the machinery on, which in the UK climate, is not always easy to plan!
Your YO does seem very sensible imo!
I think this is just part and parcel of a small private yard. I was on similar before I got my own place. The YO kept taking bits of the already small field for solar panels, veggie patch, poly tunnel etc. Field got very poached and YO asked us to find another field for a few months in order to rest their land. I was really annoyed as yes it needed rested but as they were charging me rent, I thought they should be sourcing the new field not me....long and short of it we found a field along the road which meant we wouldn't be using yard at all other than for storage and farmer was charging nearly the same price for us to use field as I was paying in livery. So I said to YO you can't charge us for something you are supposed to be providing (grazing) then expect us to pay someone else for it on top of livery. So I politely said, I'm happy to pay you livery and you can come to an agreement with farmer or I will pay farmer direct and only pay a token as livery to store my stuff while horses were grazing the other field. We had an open, calm discussion about it and I pointed out that its their choice to have horses on the land and take the rent so either you stop it altogether and don't get livery money or by accepting livery money you have to ensure you are providing what people are paying for....grazing one way or another (we bought in our own hay and supplemented the lack of grazing most of the time). I have to admit I was quite happy with the set-up once it was agreed I wouldn't have to pay double. I think you are perhaps winding yourself up about the field shelter and hose a bit, I don't really see the problem there, you'll be glad of the grazing in summer but I can understand how small things build up and escalate like this but in reality take a deep breath and look at the bigger picture. If you had to pay £40 on top for additional grazing I would be upset. It doesn't really matter how cheap your yard is perceived to be on the face of it, it's all relative and a 50% increase to anyone would be a nightmare and throw your budgeting to pot. Deep breaths OP and look at the bigger picture its not that bad
... 10/10 for wonderful feed back ... I have come to terms with the sheep I think it was more about the way she has dealt with it TBH...I would have been happier had she communicated with us... She offered to watch the sheep as they were lambing early it just so happens that they have access to what our horses don't... Again thank you. 
Ragwort poisons sheep too!
