at best you can use a flexible adhesive with a latex aditive, however this ma not bridge the cracks in the concrete if they are bigger than a hairline crack..
also if the tiles are cracked the waterproof membrane may have been compromised and if the unit us above another unit (ie not ground floor) then the shower may leak into the downstairs dweling leaving your daughter open to legal actoin for repairs.
so it pays to get it repaired by a professional