August sun here is no joke with a toddler, so shade planning is sensible. Malagueta is the convenient one – walkable from the centre, lifeguards, toilets, chiringuitos – but you are right that it is open. The fix is to hire a sombrilla and two loungers from a chiringuito for the day, or go early and leave by noon.
For calmer, quieter water within reach, Playa de la Caleta just east of Malagueta is a touch less busy, and Pedregalejo further east has small bays broken up by breakwaters, which keeps the water flat and shallow – good for little ones. Both have restaurants right behind the sand where you can retreat for lunch and a nap.
If you are willing to travel, Rincón de la Victoria is a short train-then-bus or drive and is very family-oriented. Our
Málaga beaches guide has the honest rundown of each. Will you have a car, or are you relying on buses and taxis?