Some parishioners have apparently received the impression that families with children must attend the 11.15am Mass. This is not true. Families and children are welcome at all Masses.
The 11.15am Mass is known as the 'family' Mass because the hymns and ambience are supposed to be particularly appropriate for children, but it is certainly not compulsory for children to attend this Mass.
Indeed, there may be a case for some families to try going to other Masses, since the 11.15 Mass has become so popular that many people are forced to stand at the back. This can be very boring for children (try staring at the back of serried ranks of coats and jumpers for a while to get the impression of what it's like from the lower perspective of a child). At other Masses it's much easier to sit nearer the sanctuary, which means that children can see what is going on and you, as a parent, can explain it.
And don't worry about noise. Sure, there's a greater level of background sound at the 11.15 Mass, so it doesn't seem so noticeable if your child pipes up with an embarrassing comment (mine regularly inquire, often around the creed, how much longer it’s all going to take), but children do usually adjust their volume according to the background sound. Lots of noise means children have to shout get your attention, less sound translates into quieter kids. And if things get out of hand and he or she is crying and it’s not going to stop, then simply take the child out for a while (I recommend a trip to the Parish Hall for a biscuit break).