spouse visa application from inside UK on no visa at all now

[rp51]

this maybe a complicated one, i cant seem to get any help from anyone

i met my partner who i'm marrying in 3 weeks, 4.5 yrs ago, we have now 2 2.5 yrs British born boys,

she has a Spanish permanent residence but a Argentinian passport as she works and has a house in Spain. she has been in and out of the UK within the 6 months time limit for visitors ever since we met, she works as an architect in Spain part time.

we have just received a letter saying they are going to deport her, can they do this and what do we need to do.

we have so far been told , but not sure if its correct that she needs to apply from Spain, the problem is she cant live there with the children as we cant afford it and i work here in the UK.

can we do this from the UK as if not then the children will have no mother while this goes on, does anyone know how long it can take