Zatzi - you really must complain about the staff member at the hospital writing to your sister-in-law. That is appaling and simply must be reported.
Being ignored and lost is not normal, but it is pretty normal to have minimal care prior to 12 weeks, simply becasue before then, a lot of women do miscarry and there is nothing they can do to help.... Sounds harsh but, from my experience, the care escalates the further along the pregnancy you go.
I have been very, very lucky so far: saw MW at 10 weeks for booking, had detailed nuchal scan on NHS in the 11-13 week "window" (the MW let us know that the sonographers at my hospital happen to be the sonographers from FMC (they are on loan apparently for 2 years..?), so the hospital has the highest accuracy rates poss!). I then saw MW at 16, 20, 24, 28, 30, 32, 34 weeks (due 36, 38, 39 and 40 week appointments too), as well as the consultant 3 times and 2 growth scans. i was measuring small at 24 and 28 weeks and was booked into the growth scans/cons appointments the same day!
Unfortunately, NHS maternity care does seem to be a postcode lottery. I had the choice of 2 hospitals - at the other hospital (which i didn't choose!) I would have had no nuchal scan and 3 less MW appointments!
I do think that, if you are not happy with the level of care you are receiving and can afford it, paying for private is prob worth it for the peace of mind. I have chosen to pay for private healthcare for other things - didn't for maternity becasue I have been more than happy so far. MW led should be totally fine if you are low risk. I would go to a unit on the site of a hospital though, just in case you need an emcs or something - there is no telling what might possibly happen!