"There is no cash in your bag, Maha."

Translation: لَيْسَ هُناك نُقود في شَنْطَتِك يا مَها.

[fr224]

Why do you need hunaka?

Also if it wasn't negative (There is cash in your bag) would it make sense to switch the order to "fi shan6atik naqoud"?

[SamirShaker]

You need it because هُناك means "there is". Without it, the meaning changes to "it's not money".
"There is no money" = لَيْسَ هُناكَ نُقود
"This is not money" = لَيْسَ نُقود

Several positive versions would be correct, including yours. You could say:

هُناك نُقود في شَنْطَتِك

في شَنْطَتِك هُناك نُقود

في شَنْطَتِك نُقود

In the positive version, هُناك can be omitted because the meaning is clear from في. There is no َلَيْس to make multiple meanings possible.

[Rafi3M]

(Are you a native speaker? If so, you're probably right.)
In the negative, without hunaaka, how does the meaning become "it's not money"?
ليس نقود في شنطتك
seems correct to me...

[SamirShaker]

Yes, I’m a native speaker and the example you provided is incorrect. It makes no sense.

[tsuj1g1r1]

You could however say ليس في شنطتك نقود, although it sounds a bit literary or archaic.