Nothing wrong with keeping her at home with you, especially if you have frequent outings to explore the (local) world around you. You dd does not need to go to school until age 5 (in the UK).
There are some structured toddler groups around, which can be useful, as children can interact with other children and adults, and get involved in messy play which you may prefer done outside your home.
Cost can be an issue... a nursery will typically charge - there are very few state run nurseries. A pre-school tends to be lower cost, but still charged. Structured toddler groups, such as those provided by SureStart Family Centres are often not charged for, though appreciate a voluntary contribution for snack time.
If your dd has an August birthday, you may find she has funding for a pre-school nursery place from September - check with your local borough council for local funding situation.
A few mornings/afternoons of pre-school/nursery can be quite useful. Mornings are better, as children may be tired in the afternoon. Childhood is supposed to be fun, so I would personally avoid anywhere too structured... children learn through play, so try to find a pre-school / nursery which has that ethos. Pre-School's will more likely fit the bill - as the Pre-School Learning Alliance used to have a strapline of Learning Through Play.