Meal planning, definitely check out Batch From Scratch by Lidl. And go through your bills/subscriptions to see where you can make cuts. Also, is it worth looking for a new role with a pay-rise? Now your child is older, is it possible to reduce childcare costs and rope in some willing friends/family? Are you claiming everything you can in terms of child benefit/funded hours?
Follow some of the money saving parents on Instagram. Lidl plus for shopping is good - we find it cheapest supermarket, if you spend £250 in a month, you get 10% off next shop. I try and do a bigger shop with the 10% off, stocking up on cleaning products, dry foods etc. I meal plan and use slow cooker a lot, use bored of lunch books. I freeze extra portions or have for lunch. Try and use energy at cheaper times of day, use a debit card that offers cashback. Use TopCashback for online shopping. By things for Xmas and birthdays when on sale e.g Amazon prime, Lidl middle aisles sales. Shower with child instead of separately. Cut down subscriptions. Follow martins money