'She is very concerned about her': Madonna's daughter Lourdes 'helping to heal her mother's rift with Rocco Ritchie' as star concedes defeat in custody fight

Madonna's 19-year-old daughter Lourdes is acting as a mediator between her mother and estranged son Rocco Ritchie, according to a new report.

The Sun report that Madonna is hoping Lourdes can help persuade Rocco, 15, to speak to her directly, amid a bitter custody row with her son's father, Guy Ritchie.

Madonna has not seen her son since November when he refused to return to her care after visiting his film director father in London, but the singer's oldest child Lourdes is thought to have stepped in to help heal the rift. 

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Stepping in: Madonna's 19-year-old daughter Lourdes is acting as a mediator between her her mother and estranged son Rocco Ritchie, according to reports 

A close friend has told The Sun that  'Lourdes is very concerned about her mother. Madonna has no official access or way of knowing what's going on in Rocco's life.'

It's claimed Lourdes is helping her mother get direct access to Rocco, amid her frustrations as their custody hearings continue. 

The friend added that Madonna is concerned not only for her own relationship with Rocco, but that of him and his siblings, who include David and Mercy, both ten. 

'Madonna seems close to some sort of stress-induced meltdown. This is her only son by blood — their bond was incredibly strong,' claims the source. 

See Madonna updates as Lourdes is 'helping to heal mother's rift with Rocco Ritchie'

Stressful time: Madonna is reportedly hoping Lourdes can help persuade Rocco, 15, to speak to her directly, amid a bitter custody row with her son's father, Guy Ritchie

Worried: A close friend has told The Sun that 'Lourdes is very concerned about her mother'

The insider adds that the superstar is 'proud' of her daughter, who is currently studying at the University of Michigan, her mother's former college, and 'believes she is proof of what a brilliant mum she was because she is now at university.'

A representative for Madonna has been contacted by MailOnline for comment. 

The custody battle stress saw Madonna break down on stage on Friday as she continued her Rebel Tour in New Zealand.

Drawing attention to their estranged relationship, the 57-year-old is said to have emotionally professed her love for her son to the crowd.

Close ties: Close: The star is said to be concerned that Rocco is losing touch with not only her but his siblings too, who also include David and Mercy, both ten

The mother-of-four burst into tears on the Auckland stage as she told fans: 'There is no love stronger than a mother for her son. If I talk about him too much I might cry.'  

She then dedicated her song La Vie en Rose to him and said: 'I hope he hears this somewhere and knows how much I miss him.' 

The face-off started in December when Rocco left his mother's world tour to fly to Britain to stay with his father - Rocco then allegedly breaking a court order by refusing to return to the US for Christmas.

Public declaration: Madonna broke down over her son on stage in New Zealand on Friday, with The Mail On Sunday revealing that the 57-year-old pop star tells friends that she has 'lost the battle' and has finally admitted that her son does not want to live with her

And with Rocco refusing to acknowledge his mother's many pleas and demands for him to return to the US, the teenager has stayed in England, where he has been frequently spotted enjoying time alone with his father. 

However it appears that Madonna has accepted she is fighting a losing battle, since The Mail On Sunday revealed that she admitted to friends that her son does not want to live with her.

But she is said to be 'utterly bereft' at the prospect and, as part of the peace deal, she is demanding a series of assurances that she'll retain some parental influence over her only natural son. 

Last week, as a fresh legal bid was launched at the Family Division of London's High Court, a judge urged the couple to settle their differences out of court.

Staying with dad? Madonna is said to have conceded defeat to Rocco's dad, her ex-husband, Guy Ritchie (here in August 2015) over which parent he would reside with

One of the singer's closest friends last night conceded: 'The fact is Madonna has now accepted Rocco isn't coming home and that his home is now with his dad. Rocco wants to be with his dad but she won't give up being his mother.

'She won't stop fighting to try to make sure Rocco is kept safe and has what he needs. She can't understand why it has come to this. Her world has been shattered.'

The temporary truce comes after weeks of stalemate negotiations between lawyers for Madonna, Guy and their son (who was represented by a lawyer at meetings as well).

Letting him go? It appears that Madonna (pictured with Rocco in 2013) has accepted she is fighting a losing battle, telling friends that she will let her son stay in Britain but is 'utterly bereft' at the prospect