I don't know what's average. Mine is in higher groups for year 2 but i guess the range of abilities varies from school to school. And different dc have different strengths. Might be great at one thing, not so great at another.
At end of year 1 -
For maths: she could write numbers to 100 (and further) and order them. So if she's given a sequence with a few missing she'd be able to write them in.
Twos, fives and tens - counting in.
Number bonds, just about to 20 - she was still struggling on some of the larger value ones at the end of y1. I think some subtraction mainly using a number line/grid. Know that if you've got four cakes and two people they get two each. Know that if you have three cats with four legs to work out how many legs would be 4+4+4 but also 3x4 - without necessarily knowing (without counting) that it's 12. Recognising different coins and which ones you'd need to pay for something for 54p say. Towards end of year 1/beginning year 2 working out what change they'd get.
Tell the time in terms of quarter past, half past, quarter to, oclock.
Starting to weigh and measure things.
Literacy - I think it depends on what reading level they're on. But mine has very messy writing but was using capital letters, full stops and finger spaces. Spelling - hit and miss but was doing it phonetically which teacher said was good. I was told it's the content of the writing that's important at this stage.
I think there's quite a lot on the internet about expected levels for year 1. They have SATS at the end of year 2. And there's a lot of information on the different levels and what they need to be doing to reach them. The www.education.gov.uk - gives you info on what they ought to be learning by the end of year 2 (key stage 1).
TBH I wouldn't worry too much. Things seem to suddenly click when you're least expecting them to. I thought my dd's maths was not coming on well in year 1 but by the end and in the early part of year 2, things just seemed to click with her.
Just keep reading and recognising full stops, capital letters, speech marks etc and keep asking everyday maths questions as part of everyday life. Also explaining the meanings of new words. Getting her to write shopping lists, xmas lists, little stories or poems - just using writing as much as possible.
Just my view as a parent.