Brittany Cartwright Offers Ally Lewber Advice After James Kennedy Split

Brittany Cartwright is rallying around a fellow "Vanderpump Rules" alum ... dishing out breakup advice to Ally Lewber after her highly-publicized split from James Kennedy.

We caught up with Brittany -- who previously starred on 'VPR' with James for several seasons -- and she gave us her 2 cents on her former costar's big breakup drama ... and made it clear she's in Ally's corner right now.

Having gone through a high-profile split herself -- Brittany is divorcing fellow "The Valley" star Jax Taylor -- BC advised Ally to tune out all the chatter in the press and to focus on herself.

As she put it ... Ally needs to "stay strong" and put herself first in the aftermath of the breakup ... as Brittany knows just how "tough" it can be to have your personal life play out in the media.

Though, Brittany then went on to tell our photog about her own "roller-coaster" relationship with her estranged husband ... but, we can't blame Brittany for putting the real in reality TV.

As you know, Ally confirmed her split from James this week after he caught a major break in his domestic violence case. Ally said she was glad prosecutors decided not to file charges against the DJ ... but noted they had split for good following the drama.

She said James' arrest was sparked from an argument they had outside his home related to his drinking again ... but claimed she had not been hurt in the incident.

The situation was enough to cause a permanent rift between the two ... as they've officially gone their separate ways.

Sounds like Ally needs to join Brittany for a girls' night out soon!!!