Horizontal relationships in a TD style flowchart

I do a lot of work in humanities with relationships between persons, especially creating family trees of complicated semi-inbred families (yay for history).

Could we have support for a way to demonstrate a horizontal relationship in a vertical tree? The render might look something like this

Stan ----------- Jane
     /    |    \      
    /     |     \
  Bob   Jason  Sally ------ Andrew
                        |
                        |
                     Brandon

Possible Syntax in Mermaid Here the () make a group, but this may interfere with other existing functionality.

(Stan === Jane) --> Bob & Jason & Sally
(Sally === Andrew) --> Brandon

A Close Example in Current Mermaid This is close, but has too many lines and no clear relationship between marriages.

graph TD
	Stan & Jane --> Bob & Jason & Sally
	Sally & Andrew --> Brandon

If this has been addressed or can be accomplished through another method, please let me know!

[bokobok]

Did this:

graph TD
    Parent1 --> p1p2( )
    Parent2 --> p1p2

    Parent3 --> p3p4( )
    Parent4 --> p3p4

    p1p2 --> Child1
    
    Someone1 --> c2x1
    Child2 --> c2x1( )

    p1p2 --> Child2
    p1p2 --> Child3
    Child4 --> c4c5( )
    Child5 --> c4c5
    p1p2 --> Child4

    p3p4 --> Child5
    p3p4 --> Child6
    p3p4 --> Child7
    p3p4 --> Child8

    c2x1 --> SubChild1

    c4c5 --> SubChild2

[fhShawon]

@matheusfillipe I tried like this.

flowchart
    style Grandparents fill:#fff,stroke:#000
    style Parents fill:#fff,stroke:#000
    style UncleAunt fill:#fff,stroke:#000
    style Siblings fill:#fff,stroke:#000
    style Cousins fill:#fff,stroke:#000
    style Grandfather fill:#9ddecc,stroke:#000
    style Father fill:#9ddecc,stroke:#000
    style Aunt fill:#9ddecc,stroke:#000
    style Brother fill:#9ddecc,stroke:#000
    style Sister fill:#9ddecc,stroke:#000
    style Cousin1 fill:#9ddecc,stroke:#000
    style Cousin2 fill:#9ddecc,stroke:#000
    style Cousin3 fill:#9ddecc,stroke:#000
    style Grandmother fill:#fff,stroke:#000
    style Mother fill:#fff,stroke:#000
    style Uncle fill:#fff,stroke:#000

    subgraph Grandparents[ ]
        Grandfather((Grandfather)) === Grandmother((Grandmother))
    end

    subgraph Parents[ ]
        direction RL
        Father((Father)) === Mother((Mother))
    end

    subgraph Siblings[ ]
        Brother((Brother)) -.- Sister((Sister))
    end

    subgraph UncleAunt[ ]
        direction RL
        Uncle((Uncle)) === Aunt((Aunt))
    end

    subgraph Cousins[ ]
        Cousin1((Cousin1)) -.- Cousin2((Cousin2)) -.- Cousin3((Cousin3))
    end

    Grandparents --- Parents
    Grandparents --- UncleAunt
    Parents --- Siblings
    UncleAunt --- Cousins