Apologies for my abrupt post. Phone rang before i had a chance to respond in a more civilised manner!
Are you in th SW? for example, we use washing machine 5+times a week, good economical dishwasher once a day, non-power shower, dd baths perhaps 3 times a week. Ours is £50pm approx, based on 3 of us. This is for water + wastage charge. Have not included newborn, as he is only 8wks so no bill for that period yet. We are in the SW (SW water), and our annual rates would have been around the same. Maybe we save £50 a year.
How old is DD? She is likely to need more baths as she grows older, or take showers, do you have plants which need watering regularly - indoors/outdoors? Do you have/could you have a water butt to collect water to water them? Is your washine machine/dishwasher old (older models use more water). Is your cistern an economical cistern? (older models use more water, newer models are/should be fitted with water saving flushes). Do you own your property and think you might sell (once it is installed, it cannot be removed if you change your mind, after the first year, at least down here). Are you planning/might you plan on more children in the future? Do you do watersports/have access to muddy activities that might require more washing of clothes/showering? (for example we live near the beach and in the summer spend most weekends and often time in the week on the beach getting sandy/muddy/covered in salt water, in the winter we get muddy stomping in the countryside = more showers, more washing of clothes). the number of bedrooms make no difference, it is the number of people in it for water meter.
Some of my friends are able to get theirs down to £25pm with no children by being extra extra careful all the time. I have one lot of friends who pays £20 with one child, but they shower perhaps less than they should .
It really is not as simple as will it save you money or not save you money, depends on the above. Your local provider should do an online calculation option, where you enter approx details in (ho many toilet flushes per day etc) and converts into water consumption and average usage cost per year based on that info, to give you a rough idea.