At two, while you certainly can begin working on alphabet and numerals and counting, I tend to feel that the most important things are creativity, emotions, and breadth of experience.
By breadth of experience I mean to encounter a lot of different things, such that not only can the child learn about new concepts, vocabulary, cultures, and ideas, but the child can find things that are very interesting to her specifically. As a preschool aged child (3-4), it's very common to dig deeper rather than broader in my experience; starting early to have a very broad base is important.
The action item here is to have a lot of different kinds of books. Books from other cultures; books about trains, cars, animals, flowers, and other real things; beginning storybooks that show different emotions.
Emotions are very specifically important, because reading about different emotional experiences can give your daughter the ability to express her own feelings more fully. Reading about a child who loses her toy and is sad helps her cope with losing her own toy.
Reading about a child who is pushed to the ground by another child helps her understand how to cope with that - or helps her understand how another child that she pushes feels. Giving her that vocabulary can be very useful for the next year or two, which are often very difficult in part because of the lack of emotional vocabulary.
Finally, creativity is something that can be nurtured at this age. Creativity can be developed by taking what she reads and helping her to add more to the story. A simple example is to start by asking "What comes next" at the end of a story. Start by beginning to make things up yourself - and then over time she'll start to join in.
One real-life example of the next step is something I did (and still do) with my now three year old with the Curious George stories (More detailed version of this in this answer). These are formulaic stories that always start with the same sentence ("This is George. He was a good little monkey, and always very curious.") Then, it introduces the setting with "One day, George was ...". He goes somewhere or starts doing something. Something happens to take his parental figure (The Man with the Yellow Hat) away, so that George is alone. He tries to be good, but something is just a bit too interesting, so he goes off and looks at it. That causes some trouble, which he then has to get out of - but ends up turning it into something helpful by the end.
When my son was about 2.5 to 3, I started making up stories with him, where he and George were both doing something together - something mundane, like going to the museum or the store. After a few times of this, he caught on, and started telling me what happened - sometimes just reiterating what I said last time, sometimes making up something new. By 3, he was able to make up stories from whole cloth himself.
Encouraging creativity like this - whether by making up stories, or just thinking about what else is going on - not only teaches them creativity itself, but also helps them begin to think critically about what they're reading. In order for my son to come up with a George story, he has to understand the formula to some extent. Talking about what Peppa does after she finishes jumping in muddy puddles means she has to think about what Peppa might enjoy doing. The answers might not be particularly accurate or complex, but starting to think about things like that not only can lead to interesting conversations but also leads to more critical reading later in life.
All in all, though, I would try to keep the focus on fun and the father-daughter experience. She likes reading undoubtedly in a large part because of the attention and the fun she has with you. The learning will come in time.
