They will have to assign you to a specific seating area as not every seat in the aircraft has the additional oxygen mask required for the lap child.
In an A330 that seat is 1H:
Code:
SM SK 0932/C/12DECLAXCPH/V
SM SK 0932 C 12DEC LAXCPH 333
A D F H
C 1 B L L L C B 1 C
2 L L L L 2
3 L L L L 3
4 L L L L 4
5 L L L L 5
6 L L L L 6
7 L L L L 7
8 L L L L 8
A D F H
. AVAILABLE <> WING F GEN FACI K GALLEY E EXIT C COT
+ OCCUPIED - LAST OFF H HANDICAP Q QUIET G GROUPS P PET
/ RESTRICTED B BULKHEAD V PREF.SEAT X BLOCKED L LEGROOM U UMNR
() SMOKING D DEPORTEE UP UP-DECK Z NO FILM I INFANT R REAR
Y CHARGEABLE
Code:
SEAT NUMBER: 1 H
RESTRICTED: Y
SEAT OCCUPATION: Restricted
SEAT CHARACTERISTICS: Window and Aisle together (WA)
Seat with bassinet facility (B)
Chargeable Seat (CH)
Front of cabin class / compartment (FC)
Bulkhead Seat (K)
Leg Space Seat (L)
Preferential Seat (O)
Right Side of Aircraft (RS)