I think I have installed my new rear deraileur incorrectly, can anyone give me some advice I have replaced the derailleur on my daughters Dawes Academy 26, but I think it looks wrong.
On the lowest cog (gear 8) the derailleur looks like this: enter image description here:

I assumed that the derailleur should be more verticle. Also the small cog nearest the wheel seems to be nearly touching the rear wheel cassette.
The derailleur is a Shimano Acera, which was a like for like replacement. I also replaced the derailleur hanger too.
It does seem to work, but we haven't been for a proper ride. I'm concerned that once we are out it something will go wrong.
Can anyone give any advice?
Thanks to everyone how has replies so far.
Re. the chain is the original so it shouldnt need reducing.
Re. the B-screw here are a couple of photos. Not sure how useful they are. TBH adjusting it doesn't seem to do much.
From your picture, there are a couple of questions.

Is the B screw in the correct place.
Is the chain the correct length

Please watch this video on installing a deraillieur and 1 minute in, they mention the B screw and it's corrct position. Note the two different types of fittings, the direct bolt to the hanger, and the bolt to the tab and then to the hanger. The video shows both methods.
Or update the question with close ups of the area where you attached the derailleur to the hanger.
You didn't mention whether you replaced the chain too. If you did, please make sure it is the correct length. These links discuss more on chain length.
Chain length link 1
Chain length link 2