The Lemon Pavlova sounds delish. Will only lemons do or might I be able to get away with lime juice? I happen to have lots of limes available at the moment!
Nigella's Lemon Pavlova (from SIMPLY NIGELLA) has a pavlova base that is slathered with lemon curd before being topped with whipped cream and toasted almonds. The lemon curd can be a good quality store-bought one or home-made. Nigella suggests that if you are making your own then follow the instructions for her Passionfruit Curd recipe (from HOW TO BE A DOMESTIC GODDESS). This recipe can be easily adapted to make a lime curd instead.
For this recipe you use the seeded pulp of 10 passionfruit which is approximately equivalent to 250ml. A further whole passionfruit is also added which adds an extra 30ml of juice to make a total of 280ml. So you would need to use an equivalent amount of lime juice and this would be approximately 8-10 limes (unfortunately the juciness of limes varies quite a bit). You may also like to add the very finely grated zest of 1-2 limes to the curd when you make it. The curd should be stored in the fridge and used within 1 week of making.