help! should i let dd keep sleeping past nap time as she has a cold?

[EnormousChangesAtTheLastMinute]

if an adult has a cold, extra sleep is good... but what about babies? dd went down late for pm nap (she's crabby and won't lie flat due to lotsa snot). i should have woken her before now so she'll sleep tonight. except she's not sleeping at night because of cold - so should i let her sleep on now?
also, she is in semi-reclined postion in buggy. good enough for nap and helps her breath but would it be ok to put her in buggy overnight or bad idea as not flat etc...
all thoughts gratefully received!

let her sleep if she is overtired she will be worse tonite.

yes, had decided to do that when, guess what... they're always one step ahead . better go change nappy! thanks for reply!

let i'll sleeping babies skeep is my motto!